Question

me ajudem a resolver

Answer 1

[(4-5):2]²=[(6-5):2]²

[1/2]²=[1/2]²

1/4=1/4.........é igual.

a²+2ab+b²=[-(a+b)]²

a²+2ab+b²=a²+2ab+b².......é igual

Answer 2

Olá!

Questão 22

Note que

$2-\dfrac{5}{2}=\dfrac{4}{2}-\dfrac{5}{2}=\dfrac{4-5}{2}=-\dfrac{1}{2},$

e

$3-\dfrac{5}{2}=\dfrac{6}{2}-\dfrac{5}{2}=\dfrac{6-5}{2}=\dfrac{1}{2}.$

Daí,

$\bullet\left(-\dfrac{1}{2}\right)^2=\left((-1)\cdot\dfrac{1}{2}\right)^2=(-1)^2\cdot \left(\dfrac{1}{2}\right)^2=1\cdot\left(\dfrac{1}{2}\right)^2=\dfrac{1}{4}.$

$\bullet\left(\dfrac{1}{2}\right)^2=\dfrac{1}{4}.$

Portanto vale a igualdade do enunciado.

Questão 23

$\bullet(a+b)^2=a^2+2ab+b^2.$

$\bullet(-a-b)^2=[(-1)(a+b)]^2=(-1)^2\cdot(a+b)^2=1\cdot(a+b)^2=a^2+2ab+b^2.$

Portanto, vale a igualdade do enunciado.

Bons estudos!