5x+7x+10x-5x =17x
-3-20=-23
Ans: 17x-23
It is not differentiable at x=1 since the slope of the tangent line as x -> 1 from the right is 1 while the slope of the tangent line as x->1 from the left is -1
1.) expand
3x - 15 - 5x = 25 + 6x
2.) simplify
-2x - 15 = 25 + 6x
3.) add 2x to both sides
-15 = 25 + 6x + 2x
4.) simplify
-15 = 25 + 8x
5.) subtract 25 from both sides
-15 - 25 = 8x
6.) simplify -15 - 25 to -40
-40 = 8x
7.) divide both sides by 8
-40/8 = x
8.) x = -5
