Answer:
21
Step-by-step explanation:
21212121212121213121212
Answer: b/a = -8
Step-by-step explanation:
When we have a quadratic equation:
y = a*x^2 + b*x + c.
The vertex of this function (and the axis of symetry) is located at:
x = -b/2a
Now, we know that the axis of symmetry is at x = 4.
then we have:
4 = -b/2a
And we want to find b/a.
Then we start with:
-b/2a = 4.
first we multiply by 2 in each side:
2*(-b/2a) = -b/a = 2*4 = 8.
now we multiply by -1 in each side:
-1*(-b/a) = b/a = -1*8.
Then we have: b/a = -8
For company a ( $376 + $12 an hr) it would take 2 hours because 376+12= 388+12= 400 (376 + (12 x 2) )
for company b, ( $280 + $15 ) it would take 9 hours because 280 + 15 = 295 + 15 =
310 + 15 = 325 + 15 = 340 + 15 = 355 + 15 = 370 + 15 = 385 + 15 = 400 (280 + (15 x 8))
376 x (12 x 2)
376 x 24 = 400
280 x (15 x 8)
280 x 120 = 400
1) a = 2 hrs
b = 8 hrs
2) $400
1 and 3 are proportional.
2 and 4 not proportional.
For it to be proportional, y = kx, where k is a constant.
For 1, y = 2x
For 3, y = -3x
So those are proportional