Answer:
x=12
Step-by-step explanation:
The two angles make a straight line, which is 180 degrees
10x-20 +6x+8 = 180
Combine like terms
16x -12 = 180
Add 12 to each side
16x-12+12 = 180+12
16x =192
Divide by 16
16x/16 = 192/16
x =12
The answer is 6 (x + 5) (x - 5)
7.48÷68=0.11
The sale tax rate is 0.11