## anonymous one year ago solve 3/4 x -7 = 8 11.25 20 4/3 3/4

1. anonymous

@Kitty449

2. anonymous

Okay, instead of just giving you the answer, I can help you understand how to do it if you're willing to take the five or so minutes it will take.

3. anonymous

20

4. anonymous

its better if you tun the fraction into a decimal first. so it 0.75x-7=8 then you do the same thing we did in the last one.

5. anonymous

ok thanks. :D

6. whpalmer4

@kitty449 strongly disagree that you should turn fractions into decimals! What if you have a repeating decimal? What if I gave you a problem with $$1/97$$ as a fraction? Even if you are going to write it with repeating decimal notation, there are 96 digits in the repeating portion! Also, converting to a decimal makes it more difficult to spot possible cancellations and factors. Do you recognize that 0.00952381... can be factored as $\frac{1}{3}*\frac{1}{5}*\frac{1}{7}$I'm guessing probably not. But it isn't hard to work that out from $$\dfrac{1}{105}$$ which is the fraction whose decimal expansion starts with that string of digits. Work the problem without decimals: $\frac{3}{4} x -7 = 8$ Add 7 to both sides: $\frac{3}{4}x-7+7 = 8+7$$\frac{3}{4}x = 15$Multiply both sides by 4$4*\frac{3}{4}x = 4*15$$3x = 60$divide both sides by 3$\frac{3x}{3} = \frac{60}3$$x=20$ Checking the answer: $\frac{3}{4}x-7=8$substitute our answer$\frac{3}{4}(20)-7=8$$15-7=8$$8=8\checkmark$ True statement obtained by putting our answer in original equation, so our answer is correct. No muss, no fuss, no need for any calculating devices.