Answer:
b = 10
Step-by-step explanation:
The area (A) of a triangle is calculated as
A = 
bh ( b is the base and h the height )
Here h = 3x + 15 and A = 15x + 75, thus
× b × (3x + 15) = 15x + 75
Multiply both sides by 2 to clear the fraction
b(3x + 15) = 30x + 150
Divide both sides by (3x + 15)
b = 
← factor numerator and denominator
= 
← cancel the factor (x + 5) on numerator/denominator
= 
= 10
Answer:
400 ft²
Step-by-step explanation:
The maximum area of a rectangle results from it being a square. The rectangle (or square) must have 4 equal sides in order to maximize area. But in this case, one side is a wall. That means that the remaining three sides will be = 60 / 3 = 20 feet long. You formed an square that is 20 ft x 20 ft = 400 ft²
There would be 35 rulers.
In order to solve this, use cross multiplication.
6/10 = 21/x -----> cross multiply
10*21 = 6*x
210 = 6x
35 = x
25 minutes!! you were very close, you just needed to translate the fraction to minutes!
