Answer:
y-7=4x(x+3)
Step-by-step explanation:
(The 4x is 4 times ...)
Answer:
25 miles per hour
Step-by-step explanation:
Given



The joint variation can be represented as:

Where:

Required
Find V, when: 
We have:

Express as an equation

Where k is the constant of variation
Make k the subject

When: 
We have:



When: 
We have:

Substitute:
and 

Make V the subject



Answer:
15 inches
Step-by-step explanation:
42 = 2L + 2(6)
first, we need to isolate L.
solve 2(6) to make this easier
42 = 2L + 12
42 - 12 = 2L + 12 - 12 ( this cancels out 12. )
30 = 2L
30 ÷ 2 = 2L ÷ 2 ( this cancels out 2. )
15 = L