Question

Qual e o valor de y2 - x4 quandoy = 9 e x = 2 ?

Answer 1

$\Large\boxed{\begin{array}{l}\sf y^2-x^4\bigg|_{x=2~~y=9}=9^2-2^4\\\\\sf y^2-x^4\bigg|_{x=2~~y=9}=81-16\\\\\sf y^2-x^4\bigg|_{x=2~~y=9}=65\end{array}}$