She earned $13 per hour for gardening and $10 an hour for office work.
Answer:
3<x<5
Step-by-step explanation:
5<2x-1<9
Add 1 on all the sides because of the inverse operation.
Which is 6<2x<10
The divide 2 on all sides to isolate x.
Which is 3<x<5.
Answer:
Margret need to get 4 boxes of cookies.
Step-by-step explanation:
Total friends = 3
Cookies each friend will get = 8
Each box has cookies = 6 cookies
How many boxes does Margret need to get?
Total cookies will be= Total friends x Cookies each friend will get
Total cookies will be= 3 x 8 = 24
If one box has 6 cookies and we need total 24 cookies so, divide 24 by 6 to get number of boxes
Number of boxes = Total cookies/ number of cookies in one box
Number of boxes = 24/6
Number of boxes = 4
So, Margret need to get 4 boxes of cookies.
Answer: f(x) = -0.016x² + 1.6x
Step-by-step explanation:
If the lenght of the road over the arch is 100m, we can consider a coordinate plane and say that the road starts at point (0,0) and finishes at (100,0). The vertice of the parabola is at point (50,40), because the maximum height is 40 and it is always in the middle point of the roots.
So, we have
(0,0) (50,40) (100,0)
A quadratic function is always on the form: f(x) = ax² + bx + c
0 = a0² + b0 + c
40 = a50² + b50 + c
0 = a100² + b100 + c
0 = a0² + b0 + c → c = 0 ∴
40 = a50² + b50
0 = a100² + b100
_________________________
2500a + 50b = 40 (*2)
10000a + 100b = 0
_________________________
5000a + 100b = 80
10000a + 100b = 0 (-)
__________________________
-5000a = 80
-a=80/5000
a=-0.016
∴
2500a + 50b = 40
2500.(-0.016) + 50b = 40
-40 + 50b = 40
50b = 80
b = 80/50
b = 1.6
This way f(x) = -0.016x² + 1.6x
P = -16
Subtract 7 from both sides to isolate the variable.
