Answer:
Step-by-step explanation:
if the ratio is 8:11 then 40:x
Cross multiply
8 40
11 x
8x=440
And divide by 8
x=55. She has 55 books
The answer would be y=x-4
Answer:
∠1 = 72°
Step-by-step explanation:
Complementary angles sum to 90°, thus
∠1 + ∠2 = 90, substitute ∠1 = 4∠2 , thus
4∠2 + ∠2 = 90
5∠2 = 90 ( divide both sides by 5 )
∠2 = 18°
Hence ∠1 = 90 - 18 = 72°