Вправи: 809

809. Розв’яжіть рівняння:

a) x-15 + x-23 = 2 - x-215; 3x-1+ 5(x-2)15 = 30-x+215;

3x - 3 + 5x - 10 = 32 - x; 8x - 13 = 32 - x; 9x = 45; x = 45 : 9; x = 5.

б) -2x+16 + 2-11x9 = 23 - x-32; 32x+1+ 2(2-11x)18 = 12-9(x-3)18;

-6х - 3 + 4 - 22х = 12 - 9х + 27; -28х + 1 = 39 - 9х; -28х + 9х =

= 39 - 1;

-19х = 38; х = 38: (-19); х = -2.

в) 2(334 - 2x) + 2,5 = 129 - (-x + 23); 152 - 4x + 2,5 = 119 + x - 23;

7,5 - 4x + 2,5 = 59 + x; -4x + 10 = 59 + x; -4x - x = 59 - 10; -5x = -859;

x = -859 : (-5); x = 179; x = 189.

г) 238(13 - 3x) + 58(13 - 3x) = 1 • 8; 19(13 - 3x) + 5(13 - 3x) = 8;

193 - 57х + 53 - 15х = 8; 8 - 72х = 8; -72х = 0; х = 0.