Melanie charges $4.50 per hour when she washes cars, plus $5.00 for supplies. Which function rule represents the amount y Melanie charges to wash cars for x hours? (1 point)
a) y = 0.50x
b) y = 4.50x + 5.00
c) y = 5.00x + 4.50
d) y = 9.50x
The sale price of apples at a local grocery store is $1.35 for the first pound and $1.10 for each additional pound. Which function rule shows how the cost of apples, y, depends on the number of pounds, x?
a) y = 1.10(x – 1) + 1.35
b) y = 1.10x + 1.35
c) y = 1.35x + 1.10
d) y = (1.10 + 1.35)x
If there's a constant term, that just plugs right in. Melanie always has $5.00 for supplies.
If there's a cost which is "per" unit, that is the slope of the line. Each new unit adds some fixed amount. Melanie gets $4.50 for each new hour worked.
So, y = 4.50x + 5.00
Do the other in like wise, but note that the first unit's cost is different from the others'.
The first answer is b.
What do you think the second answer is?
Which quadratic rule represents the data in the table?
x -1, 0, 1, 2, 3
y 6, 5, 6, 9, 14
The quadratic rule that represents the data in the table is y = x^2 + 5.
Here's how to check:
- When x is -1, y = (-1)^2 + 5 = 6.
- When x is 0, y = (0)^2 + 5 = 5.
- When x is 1, y = (1)^2 + 5 = 6.
- When x is 2, y = (2)^2 + 5 = 9.
- When x is 3, y = (3)^2 + 5 = 14.
So the values in the table match the quadratic rule.