Answer:
x = -1, x = 1
Step-by-step explanation:
Factor the equation. (It's a difference of squares, so we know the form will be (a-b)(a+b).)
Test this by FOILing it out, if you're unsure. This is something it can be good to memorize!
Set it equal to 0.
Separate the two parenthetical expressions by the Zero Product Property.
Solve for x!
Answer:
a. The linear function is given by,
y = 60x + 30 [y is in $ and x is in hour and x ≥ 0.5]
= 60 [for x < 0.5]
b. The total cost of the repair job is, $ 675 .
Step-by-step explanation:
Let, the linear function describing garage charge( y in $) and no. of hours of repair job ( x in hour) be,
y = mx + c [for x ≥ 0.5] -----------(1)
where, m is the slope of the line and c is the y intercept.
Now ,
m =
= 60 ----------------(2)
Now, putting the value of m and the point (x,y) = (0.5, 60) in (1), we get,
$
⇒ c = 30 ----------------- (3)
Hence, the linear function is given by,
y = 60x + 30 [y is in $ and x is in hour and x ≥ 0.5] ------------(4)
= 60 [for x < 0.5]
Now, putting
x = 4 hr 15 min
= hour
= 4.25 hour in (4), we get,
[in $]
= $ 285
So, the total cost of the repair job,
= $ (285 + 390)
= $ 675