Question 13358
Combine like terms on the right side:

10-3x=2x-8x+40
10-3x=-6x+40


Add +6x to both sides to get all x terms to the left side:
10 - 3x + 6x = -6x + 6x + 40
10 + 3x = 40


Subtract 10 from each side:
10 - 10 + 3x  = 40 - 10
3x = 30

x= 10


R^2 at SCC