Answer:
The correct answer is y = 12x + 9
Step-by-step explanation:
There is a formula called y = mx + b where m is the slope and b is the y-intercept
The y-intercept is 9 so y = mx + 9
The slope is 12/1 or just 12 so y = 12x + 9
For example:
(4/9) x=8
Now can solve this equation multiplying each side by 9/4.
(9/4)(4/9)x=(9/4)8
x=18
To check:
(4/9)(18)=(4*18)/9=72/9=8
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
To find 10% divide by 10 so 1.07 or round to 1.08 if you like then double to
get 20% so 2.14 or 2.16 so if the bill is 10.75 you would pay 12.89 with a 20% tip
