We are asked to evaluate the expression:
[tex]\frac{x^2y}{-9}[/tex]
when x = 1 and y = -7
so we replace them as shown below, making sure we include them inside parenthesis to keep clear that the expressions in x and in y are multiplying each other:
[tex]\frac{x^2y}{-9}=\frac{(1)^2(-7)}{-9}=\frac{-7}{-9}=\frac{7}{9}[/tex]
So we see that x^2 becomes 1 and the factor y stays as -7. The final expression cancels out the negative sign in numerator (from -7) and in denominator (from -9) and gives 7/9.
