Question

sendo A = ( 7 + 1/7 )^2 e B = ( 7 - 1/7 )^2, calcule ( A+B )^2

Answer 1

A =  7 +  1/7  = 7 inteiros +1/7  = ( 7 * 7 ) + 1 = 50/7 ***
(A)² =  ( 50/7)² 

B =  7 - 1/7  = 7 inteiros  -1/7  =  ( 7 * 7 ) - 1 = 48/7 ***

( B )² = ( 48/7)² = 

( A + B)² = [ ( 50/7)²  + ( 48/7)² ]²  = [(50/7)²]² + 2. (50/7)² .(48/7)² + [ (48/7)²]² =
usando  o Produto notável ( a + b )² = a² + 2ab + b²
( 50/7)⁴ + 2. ( 50/7)².(48/7)² + (48/7)⁴ *****