Answer:
148 books
Step-by-step explanation:
The side with all the 9s and x is 12 just like its opposite side because this is a parallelogram. We can write the equation to add up the three segments; the ones on the left and right are 9-x:
9-x + x + 9-x = 12
18 - x = 12
x = 6
Divide the sale price by the original price:
56 / 89 = 0.7
Multiply by 100:
0.7 x 100 = 70%
The sale price is 70% of the original price, so the discount would be 30% (100-70= 30)
Move variable to the left. -w= -10+ 4W
-w-4W =-10
Collect like terms
-5w=-10 divide both sides by 5
