Question

Find the value of this expression if x = 1 andy = -7x2y-9

Answer 1

We are asked to evaluate the expression:

`(x^2y)/(-9)`

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:

`(x^2y)/(-9)=((1)^2(-7))/(-9)=(-7)/(-9)=(7)/(9)`

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.