Question

Sabendo que a+b= 3, encontre o monômio A, para que A + 4a²+8ab=36

Answer 1

a=3-b

A+4(3-b)^2+8(3-b).b=36

A+4(9-6b+b^2) +24b-8b^2=36

A+36-24b+4b^2+24b-8b^2=36

A+4b^2-8b^2=36-36

A-4b^2=0

A=4b^2