Question

quanto e (2x+7)elevado a 2

Answer 1

Sabemos que:

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

Logo,

${(2x + 7)}^{2} = {(2x)}^{2} + 2 \times 2x \times 7 + {7}^{2} = \\ = 4 {x}^{2} + 28x + 49$