Question

решить уравнение
a) -20*(x-13)=-220
b) (30-7x)*8=352
c) (2,8-0,1x)*3,7=7,4
d) 5/12y-3/4=1/2

Answer 1

а)-20*(х-13)=-220
-20х+260=-220
-20х=-260-220
-20х=-480
20х=480
х=480:20
х=24

б)(30-7х)*8=352
30-7х=352:8
30-7х=44
-7х=44-30
-7х=14
-х=14:7
х=-2

с)(2,8-0,1х)*3,7=7,4
2,8-0,1х=7,4:3,7
2,8-0,1х=2
-0,1х=2-2,8
-0,1х=-0,8
0,1х=0,8
х=0,8:0,1
х=8

d)5/12у-3/4=1/2
5/12у=1/2+3/4
5/12у=2/4+3/4
5/12у=5/4
у=5/4:5/12
у=5/4*12/5
у=3

Answer 2

$1)-20*(x-13)=-220\\x-13= \frac{-220}{-20} \\x-13=11\\x=11+13\\x=24 \\ \\ 2)(30-7x)*8=352\\30-7x=352/8\\30-7x=44\\7x=30-44\\7x=-14\\x=-2$
$3)(2.8-0.1x)*3.7=7.4\\2.8-0.1x=7.4/3.7\\2.8-0.1x=2/*10\\28-x=20\\x=28-20\\x=8$
$4) \frac{5}{12} y- \frac{1}{4} = \frac{1}{2} \\ \frac{5}{12} y= \frac{1}{2} + \frac{1}{4} \\ \\ \frac{5}{12} y= \frac{2+1}{4} \\ \\ \frac{5}{12}y = \frac{3}{4} \\y= \frac{3}{4} : \frac{5}{12} \\ \\y= \frac{5*12}{4*5} \\ \\ y=3$