Question

Yravneniya! 1) 0,8(x-2)+2,6=0,5(7+x) 2) -0,5(x-4)-7,3=0,8(2-x) 3) (1,2-2)(8x+5,6)=0 4) (8y+6)(1,8-0,4y)=0

Answer 1

$1) \: 0.8(x - 2) + 2.6 = 0.5(7 + x) \\ 0.8x - 1.6 + 2.6 = 3.5 + 0.5x \\ 0.8x + 1 = 3.5 + 0.5x \\ 0.8 x - 0.5x = 3.5 - 1 \\ 0.3x = 2.5 \\ x = \frac{25}{3} = 8 \frac{1}{3} \\ 2) \: - 0.5(x - 4) - 7.3 = 0.8(2 - x) \\ - 0.5x + 2 - 7.3 = 1.6 - 0.8x \\ - 0.5x - 5.3 = 1.6 - 0.8x \\ - 0.5x + 0.8x = 1.6 + 5.3 \\ 0.3x = 6.9 \\ x = 23 \\ 3) \: (1.2 - 2) \times (8x + 5.6) = 0 \\ 8x + 5.6 = 0 \\ 8x = - 5.6 \\ x = - 0.7 \\ 4) \: (8y + 6)(1.8 - 0.4y) = 0 \\ (8y + 6)( \frac{9}{5} - \frac{2}{5} y) = 0 \\ \\ 8y + 6 = 0 \\ \frac{9}{5} - \frac{2}{5} y = 0 \\ \\ y1= - \frac{3}{4} \\ y2 = \frac{9}{2}$