Answer:
#7) x = 3
#8) x = 9
Step-by-step explanation:
# 7
Well AOB + BOC = AOC so...
4x - 1 + 2x + 15 = 8x + 8 (collect like terms)
6x + 14 = 8x + 8 (subtract 8 on each side)
6x + 6 = 8x (subtract 6x on both sides)
6 = 2x (divide by 2 on both sides)
3 = x
#8
COD + BOC = BOD so..
8x + 13 + 3x - 10 = 12x - 6 (collect like terms)
11x + 3 = 12x - 6 (add 6 on both sides)
11x + 9 = 12x (subtract 11x on both sides)
9 = x
Hope this helps!!
