solved the problem

Question

a-4*b=-18

-a+3b=11

(a+b)*(a-B)?

Answer 1

(a+b)*(a-B)?   <==== should that be (a-b) ?

 

Why didyou use * for multiplication only in the first equation but not the second?

 

Anyway, by adding your two equations, you get -b = -7 so b = 7.

then using the second given equation and solving it for a, you get a = 3b - 11 = 3(7) - 11 =3(7) - 11 = 10

 

Therefore a+b = 17 and a-b= 3.

 

Finally, (a+b)(a-b) = (17)(3) = 51.