Question

77°se x+y=8 e xy=15 qual e o valor de x^2+6xy+y^2

Answer 1

x + y = 8 
xy = 15

x² + 6xy + y² = 0

( x + y)²  = 8²
x² + 2xy + y² = 64
ou
x² + y² + 2(xy) = 64
x² + y² + 2( 15) = 64
x² + y² + 30 =64
x² + y² = 64 - 30
x² + y² = 34 ****
logo
x² + 6xy + y² =( x² + y²) + 6(xy )= 34 + 6(15) = 34 + 90 = 124 ****