Question

descubra o valor do X
deixem o passo a passo pfv
$1 - \: \: 3x + x = 16 + 20 = \\ \\2 - \: \: x {}^{2} + 20 = 39 - 10 \\ \\ 3 - \: \: 2x + 15 = - x + 24 \\ \\ 4 - \: \: 6x - 16 + 4 = 2x - 4 \\ \\ 5 - \: \: \frac{x}{2} + 6 = 31 - 20 \\ \\ 6 - \: \: 5x + 20 = 2x + 38 \\ \\ 7 - \: \: 12x - 20 = 4x + 20 \\ \\ 8 - \: \: 24 - x = x + x \\ \\ 9 - \: \: {x}^{2} + 75 = 100 \\ \\ 10 - \: \: 2x + 26 = 100 - 42 \\ \\ 11 - \: \: x + 10 + x + 3x = 68 - 48 \\ \\ 12 - \: \: 10x + 20 = 5x + 45$

Answer 1

3___ 2x-x=24-15
x=9

4___6x-2x=-4+16
4x=-20
x=-20÷4
x=5

7___12x-4x=20+20
8x=40
x=40÷8
x=5

8___x+x+x=-24
3x=-24
x=-8