Answer:
boys = 250
girls = 150
Step-by-step explanation:
5g = 3b eq. 1
g + b = 400 eq. 2
g = girls
b = boys
From the eq. 2
g = 400 - b
Replacing this last eq. on eq. 1:
5(400-b) = 3b
5*400 + 5*-b = 3b
2000 - 5b = 3b
2000 = 3b + 5b
2000 = 8b
2000/8 = b
250 = b
From eq. 2
g + 250 = 400
g = 400 - 250
g = 150
Check:
from eq. 1
5*150 = 3*250 = 750
Answer:
60
Step-by-step explanation:
Google "Area of a trapezoid formula" and that will help you with this
18 I think is a
19 I think is b
Don't quote me
Answer:
x = 1/2 , x = -1/2
Step-by-step explanation:
Given equation;
169x² - 42.25
Find:
Solution of equation using square root
Computation:
169x² - 42.25
We know that 13² = 169 and 6.5² = 42.25
So,
[13x]² - [6.5]²
a² - b² = (a + b)(a - b)
So,
[13x]² - [6.5]² = [13x + 6.5][13x - 6.5]
So,
13x + 6.5 = 0 , 13x - 6.5 = 0
x = 6.5 / 13 , x = -6.5 / 13
x = 1/2 , x = -1/2