Question

Решите пожалуста номер 860

Answer 1

1)
$1.1x-2 frac{1}{2}= frac{3}{5}x \ \ 1.1x-2.5=0.6x \ 1.1x-0.6x=2.5 \ 0,5x=2.5 \ x=2,5:0,5 \ x=5$

2)
$6.75x=2 frac{1}{4} x-9 \ \ 6.75x=2.25x-9 \ 6.75x-2.25x=9 \ 4.5x=9 \ x=9:4.5 \ x=2$

3)
$16-9 frac{1}{2} y=3y+21 \ \ 16-9.5y=3y+21 \ 3y+9.5y=16-21 \ 12.5y=-5 \ y=-5:12.5 \ y=-0,4$

4)
$1 frac{1}{4} y+7.5=5y \ \ 1.25y+7.5=5y \ 5y-1.25y=7.5 \ 3.75y=7.5 \ y=7.5:3.75 \ y=2$

5)
$0.5x-7=- frac{2}{3} x \ \ 0.5x*3-7*3=-2x \ 1.5x-21=-2x \ 2x+1.5x=21 \ 3.5x=21 \ x=21:3.5 \ x=6$

6) 
$6y-2 frac{4}{5} =2.5y \ \ 6y-2.8=2.5y \ 6y-2.5y=2.8 \ 3.5y=28 \ y=28:3.5 \ y=8$