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anonymous
 one year ago
ACT study prep help
anonymous
 one year ago
ACT study prep help

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0what is the sum of the 2 equation x^22x15=0

phi
 one year ago
Best ResponseYou've already chosen the best response.2can you rephrase the question?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0thats what it says what is the sum of the 2 solutions to the equation x^22x15=0

phi
 one year ago
Best ResponseYou've already chosen the best response.2ok, that makes more sense. (Your first post left out "solutions")

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ohhhh ok do u understand it cuz i dont

phi
 one year ago
Best ResponseYou've already chosen the best response.2to find the solutions you can factor the expression this is a bit involved. the first step is notice the last number: 15 the minus sign means the solutions will have opposite signs (one will be + and the other ) (if it were +15, the solutions would have the same sign, either both + or both )

phi
 one year ago
Best ResponseYou've already chosen the best response.2next, look at the number in front of the "x" term: 2 because it is negative 2, that means the bigger solution is negative (and from the first step you know the other (smaller) solution is +)

phi
 one year ago
Best ResponseYou've already chosen the best response.2now we list all pairs of numbers that multiply to give you 15 (it helps to know rules of divisibility see https://en.wikipedia.org/wiki/Divisibility_rule#Divisibility_rules_for_numbers_1.E2.80.9320) the pairs are 1,15 3,5 those are the only pairs

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0soo thats means that 15 would be it cuz i dont have a 1, 5 or 3 in my choices

phi
 one year ago
Best ResponseYou've already chosen the best response.2make the larger of each pair negative (from the second step) and the smaller of each pair +, and add them +1  15 = 15 +35 = 2 if any add up to the number in front of the x (ie. add up to 2) we found the pair we write (x+3)(x5)=0 if you multiply that out using FOIL (if you know how) you get x^2 2x 15=0 which shows we have the correct factors

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0whats FOIL i remember it but what does it stand for again

phi
 one year ago
Best ResponseYou've already chosen the best response.2finally, we look at (x+3)(x5)=0 what x number makes that zero? either x+3 =0 (so x= 3) or x5=0 (so x=5) those are the solutions add them: 5+3 = 2

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok but whats FOIL again

phi
 one year ago
Best ResponseYou've already chosen the best response.2see https://www.khanacademy.org/math/algebrabasics/quadraticspolynomialstopic/multiplyingbinomialscorealgebra/v/multiplyingbinomials for how to do FOIL

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok and this whats the sum of the polynomials 4x^2y+2x^2y^3 and 2xy +x^2y^3

phi
 one year ago
Best ResponseYou've already chosen the best response.2you add them by putting + sign in between them, like this \[ 4x^2y+2x^2y^3 + 2xy +x^2y^3 \] now look for "common terms" (same variables to the same power) do you see any common terms?

phi
 one year ago
Best ResponseYou've already chosen the best response.2which terms are "common terms" ?

phi
 one year ago
Best ResponseYou've already chosen the best response.2you want terms that has the same number of x's and y's

phi
 one year ago
Best ResponseYou've already chosen the best response.2example: x^2 y and 2 x^2 y or 3x^3 y^3 and 4 x^3 y^3 (you have x^3 and y^3 in both terms.. only the number out front is different)

phi
 one year ago
Best ResponseYou've already chosen the best response.2the common terms in your problem are \[ 2x^2y^3 +x^2y^3\] you have 2 of them plus one more. you can write that as \[ 3 x^2y^3\] so the sum is \[ 4x^2y 2xy +3x^2y^3\]
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