Question

10(100-×)+2×=3(×+9)-28

Answer 1

10.(100-x) +2x = 3.(x+9) -28

1000 -10x +2x = 3x + 27 -28

1000 -8x = 3x -1

1000 +1 = 8x +3x

1001 = 11x

1001/11 = x

Resposta: 91 = x

Answer 2

$10(100 - x) + 2x = 3(x + 9) - 28 \\ 1000 - 10x + 2x = 3x + 27 - 28 \\ (- 10x + 2x - 3x = \\ \: \: \: 27 - 28 - 1000) \\ - 11x = - 1001 \\ x = \frac{ - 1001}{ - 11} \\ x = 91$