Answer:
Equivalent systems of equations review
Step-by-step explanation:
We're given two systems of equations and asked if they're equivalent.
x + 4y = 8 (1)
4x + y = 2 (2)
Interestingly, if we sum the equations in System A, we get:
Replacing the first equation in System A with this new equation, we get a system that's equivalent to System A:
This is System B, which means that System A is equivalent to System B.
Let's say the cost of student tickets is x and the cost of adult tickets is y. Then:
(1) 12y + 6x = 138
(2) 5y + 11x = 100
If we rearrange equation (1) we get:
12y = 138 - 6x
Now divide each side by 12:
y = 11.5 - 0.5x
We can now substitute this into equation (2):
5(11.5 - 0.5x) + 11x = 100
57.5 - 2.5x + 11x = 100
8.5x = 42.5
x = 5, therefor the cost of a student ticket is $5.00
Answer:
-12x-28=4
-12x=32
x=-16/3
Step-by-step explanation:
Answer:
25 in.
Step-by-step explanation:
DEC is a right triangle. <DEC is a right angle.
(DE)² + (EC)² = (DC)²
DE = ½DB = ½(48 in.) = 24 in.
(24 in.)² + (7 in.)² = (DC)²
576 in.² + 49 in.² = (DC)²
(DC)² = 625 in.²
DC = 25 in.