Answer:
12
Step-by-step explanation:
Equation y=40x+420
plur in 900 to the y
900=40x+420
subtract
480=40x
divide
x=12
Amount of tax on the book (s) is $0.72
Step-by-step explanation:
- Step 1: Given 6/100 = s/12
- Step 2: Cross multiply to solve for s
⇒ 6 × 12 = 100 × s
⇒ 72 = 100s
⇒ s = 72/100 = 0.72
The answer would be 1.25.