Answer:
5. 9 8. 
Step-by-step explanation:
a²+b²=c²
so for #5 12²+b²=15²
144+b²=225 (subtract 144 from both sides)
b²=81
b=9
For #8
9²+b²=11²
81+b²=121 (subtract 81 from both sides)
b²=40
b=
=

Answer:
He brought 3 dozen cookies
She ate
of the bag of Doritos
She read 25 books
Step-by-step explanation:
∵ Mike makes 4 dozen cookies
∵ He brings 75% of them for a party at his school
- Multiply 75% by 4
∵ 75% =
∴ He brought =
× 4
∴ He brought = 3
He brought 3 dozen cookies
∵ Sam bought a bag of Doritos
∵ She ate only 40% of them
∵ 40% = 
∴ She ate =
× 1
∴ She ate = 
She ate
of the bag of Doritos
∵ Jamie took 50 books from the library
∵ She only read half of her whole stack
- Multiply half by 50
∴ She read =
× 50
∴ She read = 25
She read 25 books
Answer:
62.8, 63% if you around it off.
Step-by-step explanation: Do 49 Divided by 78, then times it by 100 to get your percentage. I just rounded it off to the nearest tenth and whole number just in case. Hope this helped!
$630
The total perimeter is 42 and 42x15=630
Answer:
d
Step-by-step explanation:
Given y is directly proportional to x² then the equation relating them is
y = kx² ← k is the constant of proportion
To find k use the condition y =
when x =
, then
= k(
)² =
k ( multiply both sides by 8 )
1 = 2k ( divide both sides by 2 )
k = 
y =
x² ← equation of proportion
When y =
, then
=
x² ( multiply both sides by 2 )
9 = x² ( take the square root of both sides )
x = ±
= ± 3
with positive value x = 3 → d