Question

if x+y=7 and x-y=2 what is the value of x^2-y^2

Answer 1

Answer:

If    $x+y=7$   and   $x-y=2$   then the value of

$x^{2} -y^{2} = (7)(2)=14$.

Step-by-step explanation:

We know the standard equation

$x^{2}-y^{2} = (x-y)(x+y)$

Proof:

$(x-y)(x+y)=x^{2} -yx+yx-y^{2}$

                      $=x^{2} -y^{2}$

therefore $x^{2} -y^{2}=(7)(2)=14$.

thank you