X is 10
I have shown the calculation in the attachment.
Answer:
n = 12
Step-by-step explanation:
(n-8)x 7 = 28
n-8 = 4
n = 12
Answer:
y = 6x - 47
or
6x - y - 47 = 0
Step-by-step explanation:

Answer:
C = 8
Step-by-step explanation:
So to get C by itself, we need to add 12 to both sides of the equation, which is the opposite of subtracting:
C - 12 = -4
C - 12 + 12 = -4 + 12
C = 8
Answer:
Part A:
x + y = 80
x + 20 = y
Part B:
Pam spends 30 minutes practicing math every day.
Part C:
It is not possible for Pam to have spent 60 minutes practicing dance because this means she must have practiced math for 40 minutes (60 - 20 = 40). This would total out to 100 minutes of total practice, not 80 minutes. Therefore, this is impossible.
Step-by-step explanation:
Part A:
"She spends 80 minutes every day practicing dance and math."
x + y = 80
"She dances for 20 minutes longer than she works on math."
x + 20 = y
Part B:
Solve for x:
x + 20 = y
Isolate variable x:
x = y - 20
Plug in this new value for the first equation:
y - 20 + y = 80
Combine like terms:
2y - 20 = 80
Isolate variable y:
2y = 100
y = 50
Plug in the new value of y into any equation:
x + 50 = 80
Isolate variable x:
x = 30
Part C:
x + 20 = y
x + 20 = 60
x = 40
x + y = 80
40 + 60 = 80
100 = 80
Impossible.