Question

Por favor!! Respostas da c, d, e, f ❤️

Answer 1

c)

$20 - \frac{(21 - x)}{9} = 18 \\ 21 - x = - (18 - 20) \times 9 \\ - x = 18 - 21 \\ x = 3$

d)

$\frac{56x}{8} \div 7 = 4 \\ \frac{56x}{8} = 4 \times 7 \\ 56x = 4 \times 7 \times 8 \\ x = \frac{4 \times 7 \times 8}{56} \\ x = 4$

e)

$25 {x}^{2} + 200 = 300 \\ 25 {x}^{2} = 300 - 200 \\ {x}^{2} = \frac{100}{25} \\ x = \sqrt{4} \\ x = 2 \: \: ou \: \: x = - 2$

f)

$68 - x = 32 \\ - x = 32 - 68 \\ x = 36$