# What is (-5y^5 + 7y^4) -: (-y)?

May 24, 2018

$5 {y}^{4} - 7 {y}^{3}$

#### Explanation:

When dividing exponents, it is just subtraction. The $- y$ is actually $- {y}^{1}$. Since the numerator has the same variable and nothing is being multiplied or divided in it, we can just subtract $1$ from each exponent.

$- 5 {y}^{5}$ would just be $- 5 {y}^{4}$ and $7 {y}^{4}$ would become $7 {y}^{3}$.

Now the denominator is not gone. The $y$ is gone, but there is still a $- 1$ there. All this means is you need to switch the signs up top. The final simplified solution would be

$5 {y}^{4} - 7 {y}^{3}$