Answer:

Step-by-step explanation:
we have

solve for b
That means ---> isolate the variable b
Multiply by 3 both sides

simplify

Convert to mixed number

X - the unit
3x; 4x; 5x - the lengths of the sides
3x + 4x + 5x = 30
12x = 30 |:12
x = 2.5
3x = 3 · 2.5 = 7.5 cm
4x = 4 · 2.5 = 10 cm
5x = 5 · 2.5 = 12.5 cm
Answer:
13
Step-by-step explanation:
In inches, the height of the ceiling is ...
(15 ft)(12 in/ft) = 180 in
The number of times 13.25 inches will fit in this space is ...
(180 in)/(13.25 in) ≈ 13.6
Betty can fit 13 whole boxes in the space.