Question

а) 4(x + 1) + 11 = 31;
б) 7 – 2x – 3(5x – 2) = 47;
в) (2x – 0,1) + (3x – 5) = 7;
г ) (x – 0,2) + (4x – 3) = 8.

Answer 1

Ответ:

$1) \ 4(x + 1) + 11 = 31 \\ 4x + 4 + 11 = 31 \\ 4x = 31 - 4 - 11 \\ 4x = 16 \\ x = 16 \div 4 \\ x = 4.$

$2) \ 7 - 2x - 3(5x - 2) = 47 \\ 7 - 2x - 15x + 6 = 47 \\ - 17x = 47 - 7 - 6 \\ - 17x = 34 \\ x = 34 \div ( - 17) \\ x = - 2.$

$3) \ (2x - 0,1) + (3x - 5) = 7\\ 2x - 0,1 + 3x - 5 = 7 \\ 5x = 7 + 0,1 + 5 \\ 5x = 12,1 \\ x = 12,1 \div 5 \\ x = 2,42.$

$4) \ (x - 0,2) + (4x - 3) = 8. \\ x - 0,2 + 4x - 3 = 8 \\ 5x = 8 + 0,2 + 3 \\ 5x = 11,2 \\ x = 11,2 \div 5 \\ x = 2,24.$