3*25=75
so the question is 75/8
you would 10 packages since
8*8=64
8*9=72
but 8*10=80 is enough, remainder 5
Answer:
3 mph
Step-by-step explanation:
Find the following:
5 miles 5 miles
---------------- = ----------- = 3 mph
1 2/3 hr 5/3 hr
x = liters of 40% solution
y = liters of 70% solution
Gabe needs 30 liters, so
x + y = 30
Each liter of 40% solution contributes 0.4x liter of acid; each liter of 70% solution contributes 0.7y liter of acid. Gabe needs a solution with concentration 60%, which from 30 liters amounts to a net volume of 0.6*30 = 18 liters of acid. So
0.4x + 0.7y = 18
Solve the system however you like. By substitution, we have
y = 30 - x
0.4x + 0.7(30 - x) = 18
0.4x + 21 - 0.7x = 18
3 = 0.3x
==> x = 10 ==> y = 20
It looks like the length of a and b should be the same. You can use the Pythagorean theorem (only works with right triangles):
a² + b² = c² (c is the hypotenuse or the longest side of the triangle, a and b are the other side lengths of the triangle)
a² + (4)² = (5)²
a² + 16 = 25
a² = 9
a = 3
a and b have a length of 3
X² - 8x + y² = 9
(x² - 8x + 16) + y² = 9 + 16
(x - 4)² + y² = 25
(x - 4)² + y² = 5²
he radius is equal to 5.