Question

I need some help with this problem, PLEASE!! 5x-3y=11 and I need to solve for y. I did the math and came up with 11-5x/-3=y but the answer key says the answer is 5x-11/3 =y How is it a positive if you divide by -3?

Answer 1

you should get
\[ -3y= -5x+11 \\ y = \frac{-5x+11}{-3} \]
notice you divide the whole right side by -3

you might remember when you add or subtract fractions, they must have a common denominator
example:
\[ \frac{2}{3} - \frac{1}{3}= \frac{2-1}{3} \]
you can do it backwards:
\[ \frac{2-1}{3} =\frac{2}{3} - \frac{1}{3}\]

use that idea to write
\[ y = \frac{-5x+11}{-3} \\
y = \frac{-5x}{-3} + \frac{11}{-3} \\
y = \frac{5}{3} x - \frac{11}{3}
\]
or
\[ y= \frac{5x - 11}{3} \]

Answer 2

Oh how simple it seems once you know what you did wrong. Thank you so much...I knew I was just missing something simple. I think I was staring at it too long. :o)