Помогите решить уравнения:

a) 6x+4=2x+12

б) 4 * (2x+1) + x=2x+25

в) 5/18 * (0,54-7,2y) - 4/19 * (0,76-3,8y) = 0,002

a) 6x+4=2x+12

4*x+4-12=0

4*x-8=0

x=8/4

x=2

б) 4 * (2x+1) + x=2x+25

8*x+4+x-2*x-25=0

9*x+4-2*x-25=0

7*x+4-25=0

7*x-21=0

x=21/7

x=3

в) 5/18 * (0,54-7,2y) - 4/19 * (0,76-3,8y) = 0,002

(5/18) * (0.54-7.2*y) - 4/19 * (0.76-3.8*y) - 0.002=0

0.15-2*y-4/19 * (0.76-3.8*y) - 0.002=0

0.15-2*y - (4/19) * (0.76-3.8*y) - 0.002=0

0.15-2*y - (0.16-0.8*y) - 0.002=0

0.15-2*y-0.16+0.8*y-0.002=0

-0.01-2*y+0.8*y-0.002=0

-0.01-1.2*y-0.002=0

-0.012-1.2*y=0

y=-0.012/1.2

y=-0.01