Question

Решить уравнения
1) 5•(3х-4)-2•(5х-6)=7
2) -4•(½х-¾)+6•(½х-⅔)=-5

Answer 1

1) x = 3

$5 \times (3x - 4) - 2 \times (5x - 6) = 7 \\ 15x - 20 - 10x + 12 = 7 \\ 15x - 10x - 20 + 12 = 7 \\ 5x - 8 = 7 \\ 5x = 7 + 8 = 15 \\ x = 15 \div 5 = 3$

2) x = - 4

$- 4 \times ( \frac{1}{2} x - \frac{3}{4} ) + 6 \times ( \frac{1}{2} x - \frac{2}{3} ) = - 5 \\ - \frac{4}{2}x + \frac{12}{4} + \frac{6}{2} x - \frac{12}{3} = - 5 \\ - 2x + 3 + 3x - 4 = - 5 \\ x - 1 = - 5 \\ x = - 5 + 1 = - 4$