Answer:
x=-121
Step-by-step explanation:
.4(5+2x) -12 = .9x+2.1
Distribute the .4
2 + .8x -12 = .9x+2.1
Combine like terms
-10 +.8x = .9x +2.1
Subtract .8x from each side
-10 +.8x-.8x = .9x-.8x +2.1
-10 = .1x +2.1
Subtract 2.1 from each side
-10-2.1 = .1x +2.1-2.1
-12.1 = .1x
Divide by .1
-12.1/.1 = 1.x/.1
-121 =x
