Question

$7 {x}^{2} + 2 = 30$
Qual a resposta ​

Answer 1

Resposta:

$7 {x}^{2} + 2 = 30 \\ 7 {x}^{2} = 30 - 2 \\ 7 {x}^{2} = 28 \\ {x}^{2} = 28 \div 7 \\ {x}^{2} = 4 \\ x = \sqrt{4} \\ x = 2 \: ou \: x = - 2$