Question

Encontre o valor de "X"

1) 4X - 8 = 2X + 64
2) 7X - 63 = 9X - 21
3) 3X + 70 = 2X + 75
4)9X - 81 = 7X - 9
5)8X + 24 = 2X - 36​

Answer 1

Resposta:

$1) \: 4x - 8 = 2x + 64 \\ 4x - 8 - 2x - 64 = 0 \\ 2x - 72 = 0 \\ 2x = 72 \div (2) \\ x = 36$

$2) \: 7x - 63 = 9x - 21 \\ 7x - 63 - 9x + 21 = 0 \\ - 2x - 42 = 0 \\ - 2x = 42 \times ( - 1) \\ 2x = - 42 \div (2) \\ x = - 21$

$3) \: 3x + 70 = 2x + 75 \\ 3x + 70 - 2x - 75 = 0 \\ x - 5 = 0 \\ x = 5$

$4) \: 9x - 81 = 7x - 9 \\ 9x - 81 - 7x + 9 = 0 \\ 2x - 72 = 0 \\ 2x = 72 \div (2) \\ x = 36$

$5) \: 8x + 24 = 2x - 36 \\ 8x + 24 - 2x + 36 = 0 \\ 6x + 60 = 0 \\ 6x = - 60 \div (6) \\ x = - 10$