pi radians in a semicircle (half circle)
2pi radians in a full circle.
2pi = 2*3.14 = 6.28 approximately, so there are approximately 6.28 radians in a half circle.
2pi radians is equivalent to 360 degrees.
Three times the square of a number means 
Nine times a number is 
If these quantities must be equal, we have
We can divide both sides by 3 to get
Since x is non-zero, we can divide both sides by x:
Answer:
My answer is 78.55
Step-by-step explanation:
I've given the steps. Hope it really helps
Answer:
The answer is: The adult ticket costs $15 and the child ticket costs $10.
Step-by-step explanation:
Let a = the dollar amount of adult tickets and c = the dollar amount for child tickets. The child ticket cost $5 less than the adult ticket. Then:
c = a - 5
The number of adult tickets times the adult cost plus the number of child tickets times the cost for child tickets is equal to the total dollar amount. Set up the equation:
8a + 2c = $140
Substitute:
8a + 2(a-5) = 140
8a + 2a - 10 = 140
10a = 150
a = 150 / 10 = 15, so the adult ticket is $15
Solve for c:
c = a - 5
c = 15 - 5 = 10, so the child ticket is $10
Proof:
8a + 2c = 140
8(15) + 2(10) = 140
120 + 20 = 140
140 =140
