Answer:
The answer is d the one with the 18 in it
Step-by-step explanation:
To eliminate x, the coefficients of x's in both equations should be opposite numbers. Since the coefficient of x in the second equation is 3, the coefficient in the first equation should be -3. So she should multiply the first equation by -3.
The table is:
Number of washes denoted by x: 0, 8, 12
Amount left on card denoted by y: 30, 18, 12
a. Write an equation that shows the amount of dollars left on the card
Solution:
18 – 30 divided by 8 – 0 = -12/8
On simplest form is -3/2
The equation is y = -3/2x + 30
b. Explain the meaning of the negative slope above.
As the number of car washes increase, the dollars left on the card decreases.
c. What is the maximum value of x?
0 = -3/2x + 30
2/3 x 3/2 x = 30/1 x 2/3
Cancel 2/3 x 3/2 and reduce 30 by 3 we get 10, 10 x 2
x = 20
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Answer: 85
Step-by-step explanation:
Add all the numbers together than
divide by 8