Question

5x-9=3x+1
-2y+14=8y-6
11x=-4x
0,8+16=20+0,7x
6*(x-1)=12
(y+8)*(-7)=15

Answer 1

$1)5x - 9 = 3x + 1 \\ 5x - 3x =1 + 9 \\ 2x = 10 \\ x = 5 \\ 5 \times 5 - 9 = 3 \times 5 + 1 \\ 16 = 16$
$2) - 2y + 14 = 8y - 6 \\ - 2y - 8y = - 6 - 14 \\ - 10y = - 20 \\ y = 2 \\ - 2 \times 2 + 14 = 8 \times 2 - 6 \\ - 4 + 14 = 16 - 6 \\ 10 = 10$
$3)11x = - 4x \\ 11x + 4x = 0 \\ 15x = 0 \\ 11 \times 0 = - 4 \times 0 \\ 0 = 0$
$4)0.8 + 16 = 20 + 0.7x \\ 16.8 = 20 + 0.7x \\ - 0.7x = 20 - 16.8 \\ - 0.7x = 3.2 \\ x = 3.2 \div ( - 0.7) \\ x = - \frac{32}{7}$
$5)6( \times - 1) = 12 \\ 6x - 6 = 12 \\ 6x = 12 + 6 \\ 6x = 18 \\ x = 3 \\ 6(3 - 1) = 12 \\ 12 = 12$
$(x + 8) \times ( - 7) = 15 \\ - 7x - 56 = 15 \\ - 7x = 15 + 56 \\ - 7x = 71 \\ x = 71 \div 7 \\ x10 \frac{1}{7}$