-10(-4x+10)=-300

-40x-100=-300

-40x=-200

X=5

-10a+108=-64a

-10a+64a=-108

54a=-108

a=-2

26-5m=2-9m

-5m+9m=2-26

4m=-24

m=-6

-y+20=+y

-y-y=-20

-y^2=-20

y^2=20

y=2корень из 5

y=