With
, we have

Then the difference quotient is

since <em>h</em> ≠ 0.
Answer:
75%
Step-by-step explanation:
90/ 120 is the same as 75 or 3/4 so 75% of 120 is 90
7(3a + 12) = 168 ← ( divide both sides by 7 )
3a + 12 = 24 ← ( subtract 12 from both sides )
3a = 12 ← ( divide both sides by 3 )
a = 4
OR
distribute the parenthesis by 7
21a + 84 = 168 ← ( subtract 84 from both sides )
21a = 84 ← ( divide both sides by 21 )
a = 4