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anonymous
 5 years ago
A disc must play 14 commerical spots during 1 hour of a radio show. Each commerical is either 30 seconds or 60 seconds long. If the total commercial time during 1 hour is 11min, how many 30 second commercials were played that hour? How many 60 second commercials?
anonymous
 5 years ago
A disc must play 14 commerical spots during 1 hour of a radio show. Each commerical is either 30 seconds or 60 seconds long. If the total commercial time during 1 hour is 11min, how many 30 second commercials were played that hour? How many 60 second commercials?

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0let x be no. of commer. of 30 sec and y be of 60 so x*30+y*60=11*60 and x+y=14 solve 2 equations

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0x = number of 30 second spots y = number of 60 second spots x + y = 14 30x + 60y = 660 11(60) = 660 seconds 30x  30y = 420 30x + 60y = 660 30y = 240 y = 8 x + 8 = 14 x = 6 6 30 second spots 8 60 second spots

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Thanks much I have a few more would you like more medals?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Don't care about the medals... but will help you... but we will work them together.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Soybean meal is 12% protein; cornmeal is 6% protein. How many pounds of each should be mixed together in order to get 240 pounds mixture that is 9% protein?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0First of all you should see we are talking about two different concepts (pounds and percents) we will start with pounds. x = pounds of soybean meal y = pounds of cornmeal OK so far?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0OK.. what is the other number in the problem that deals with pounds and what do you think the equation is?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0So what is the equation about pounds.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Good... now we need to deal with the percents.. There are three percents listed. 12%, 6%, and 9%

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0of the mixture 12% of it is soybean protein of the mixture 6% of it is cornmeal protein and we want to mix it to be 9% protein.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so .12x + .06y = .09(240) 12% of the soybean + 6% of the cornmeal will give you 240 pounds of 9% protein. OK

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0So we have 2 equations ... 2 variables. x + y = 240 .12x + .06y = .09(240)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0x + y = 240 .12x + .06y = 21.60

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I like to multiply every term by something to get rid of decimals... or multiplying means the same thing as moving the decimal. so I am going to move the decimal two to the right on every term... same thing as multiplying by 10

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok this is where I dnt understand really I have tried it this way and I dnt get anywhere but the wrong answer.....

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0x + y = 240 12x + 6y = 2160 OK so far? I will wait for your answer

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0OOPS same things as multiplying by 100 in the last post

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0well what happen to 9%?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I took the 9% times the 240 because at the end you want 240 pounds that is 9% protein. If you look above I had .09(240) which is 21.6

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0What do you mean by right? to what?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I will write what we have right now with every step so it is all together.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0x + y = 240 .12x + .06y = .09(240) I am going to multiply .09 * 240 x + y = 240 .12x + .06y = 21.6 I am going to multiply each term by 100 x + y = 240 12x + 6y = 2160 Now is when we have to get rid of one of the letters. We can get rid of the x's or the y's. I am going to pick the y's because the 6 with the y is smaller than the 12 with the x.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0The way we do that is to multiply one equation by some number that will get a variable that will cancel out so that we are only left with one variable. for example 6y  6y = 0 another example 6y + 6y = 0 SO 6(x + y = 240) which when we distribute is 6x  6y = 1440 OK???

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Sorry I am not feeling good and I am trying to get these last few done so that I can go get some rest....

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.06x  6y = 1440 12x + 6y = 2160 Notice the y's are going to cancel out when we add 6x = 720 (I added the two equations together) x = 120 (I divided by 6) So if x = 120 and our first equation said x + y = 240 then 120 + y = 240 y = 120 so x = 120 and y = 120 120 pounds of soybeans and 120 pounds of cornmeal

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok gotcha I am trying to follow along sorry

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0that was easy 120 plus 120 then that would have been more simply

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0A student makes a $9.75 purchase at the bookstore with a $20 bill. The store has no bills and give change in quarter and fifty cents pieces. There are 30 coins in all. How many of each kind are there?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Two concepts number of coins and money. x = number of quarters y = number of 50 cent pieces. So since we have 30 coins we have x + y = 30

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Money wise we know that each quarter has a value of .25 so if you had 5 of them it would be worth .25 * 5 but in this problem we have x of them so the value is .25x same with the 50 cent pieces.. so .25x + .50y = 10.25 (we need the amount of change 20  9.75)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0x + y = 30 .25x + .50y = 10.25 (multiply second equation by 100 to get rid of decimals) x + y = 30 25x + 50y = 1025 I am going to get rid of the x's by multiplying by 25 25(x + y = 30) 25x + 50y = 1025 25x  25y = 750 25x + 50y = 1025 add the two equations. 25y = 275 (the x's canceled out) y = 11 so we had 11 50 cent pieces. Our first equation said x + y = 30 so x + 11 = 30 x = 19 so we had 19 quarters.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thanks very much.....rest time
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