Question

Решите пожалуйста, срочно надо)

Answer 1

(2х+8)/13+(15-х)/26=2

2(2х+8)+15-х=26*2
4х+16+15-х=52
3х=52-31
3х=21
х=21:3
х=7

(5-3х)/7-(4х-1)/5=-4

5(5-3х)-7(4х-1)=-4*35

25-15х-28х+7=-140
-43х=-140-32

43х=172

х=172:43
х=4

Answer 2

Ответ:

220

$a)\frac{2x+8}{13} + \frac{15-x}{26} = 2\\  \\2(2x+8) + 15 - x = 52\\\\4x - x = 52 - 16 - 15\\\\3x = 21 \\\\x = 7$

$b)\frac{5 - 3x}{7} - \frac{4x-1}{5} = -4\\ \\5(5-3x) - 7(4x-1) = -140\\\\25 - 15x - 28x + 7 = -140\\\\-43x = -140 - 25 - 7\\\\-43x = -172\\\\x = 4$

$c)\frac{9 - 2x}{4} + \frac{3x+15}{14} = 5\\\\7(9-2x) + 2(3x+15) = 140\\\\63 - 14x + 6x + 30 = 140\\\\-14x + 6x = 140 - 63 - 30\\\\-8x = 47\\\\x = \frac{47}{8} = 5\frac{7}{8} = 5,875$

$d)\frac{x+4}{6} - \frac{9 - 7x}{15} = -3\\\\5(x+4) - 2(9-7x) = -90\\\\5x + 20 - 18 + 14x = -90\\\\5x - 14x = -90 - 20 + 18\\\\-9x = - 92\\\\x = \frac{92}{9} = 10\frac{2}{9}$

223

$a)\frac{x-2}{4} + \frac{x+3}{8} = \frac{8-x}{6}\\\\6(x-2) + 3(x+3) = 4(8-x)\\\\6x - 12 + 3x + 9 = 32 - 4x\\\\6x + 3x + 4x = 32 + 12 - 9\\\\13x = 35\\\\x = \frac{35}{13} = 2\frac{9}{13}$

$b)\frac{3x-1}{28} - \frac{5-4x}{14} = \frac{7+9x}{7}\\\\(3x-1) - 2(5-4x) = 4(7+9x)\\\\3x - 1 - 10 + 8x = 28 + 36x\\\\3x + 8x - 36x = 28 + 1 + 10\\\\-25x = 39\\\\x = -\frac{39}{25} = -1\frac{14}{25}$

$c)\frac{4-5x}{18} + \frac{2x+3}{9} = \frac{7x-8}{36}\\\\2(4-5x) + 4(2x+3) = 7x-8\\\\8 - 10x + 8x + 12 = 7x-8\\\\-10x + 8x - 7x = -8 - 8 - 12\\\\-9x = -28\\\\x = \frac{28}{9} = 3\frac{1}{9}$

$d)\frac{3-4x}{3} - \frac{8+9x}{4} = \frac{9-4x}{8}\\\\8(3-4x) - 6(8+9x) = 3(9-4x)\\\\24 - 32x - 48 - 54x = 27 - 12x\\\\-32x - 54x + 12x = 27 - 24 + 48 \\\\-74x = 51\\\\x = -\frac{51}{74}$