Question

Dê o valor da letra (2/B)² = 4/25

Answer 1

$\frac{ 2^{2} }{ B^{2} } = \frac{4}{25}$
$\frac{4}{ B^{2} } = \frac{4}{25}$  -Multiplica cruzado
4B²=100
B²=100/4
B²=25
B=√25
B=5

Answer 2

(2/B)² = 4 / 25
4/B² = 4/25
B² = √25
B=+-5.