63 because both angles are the same
Answer:
(x) = 
Step-by-step explanation:
let y = f(x) , then rearrange making x the subject
y = 6x + 7 ( subtract 7 from both sides )
y - 7 = 6x ( divide both sides by 6 )
= x
Change y back into terms of x with x =
(x) , then
(x) = 
Christopher read 2 books each month which mean 4 books in 2 months