Answer:
<em>There are 12 boys and 18 girls</em>
Step-by-step explanation:
<u>Equations</u>
There are 30 students in a class. Let's call:
x = number of boys
Since the sum of boys and girls is 30:
30 - x = number of girls
The ratio of boys to girls is 2:3, thus:
Crossing denominators:
3x = 2(30 - x)
Operating the parentheses:
3x = 60 - 2x
Adding 2x:
5x = 60
Dividing by 5:
x = 60/5 = 12
x = 12
There are 12 boys and 30-12=18 girls
Answer:
C = commutative property of Addition
Answer: #20, x = 3
#21, x = 1/2
Step-by-step explanation:
#20) x + 4 + x + 2+ x + 5 = x + 3 +x+3+x+1+x+1
3x + 11 = 4x + 8
<u>-3x -3x</u>
11= x + 8
<u> - 8 - 8</u>
3 = x
#21) 12x(5) = 6x + 9 + x + 10 + x + 7
60x =8x + 26
<u> -8x -8x</u>
52x = 26
divide both sides by 52
x = 1/2
-4x + 2x = -2x
6 + 5 = 11
Therefore, 11 - 2x = 0
11 = 2x
x = 11/2 = 5.5
Kristin jogs 48 miles in 50 minutes, so her unit rate is 48miles/50 minutes
