A = (1/2) b * h
h = b - 5
42 = (1/2) * b * (b - 5)
42 = (1/2) * b^2 - 5b
multiply both sides by 2 to clear the fraction (1/2)
2(42) = 2(1/2) *b^2 - 5b
84 = b^2 -5b
Since this is a quadratic equation, subtract 84 from both sides so that it is set = to zero.
b^2 - 5b - 84 = 0
Now factor.
(b - 12)(b + 5) = 0
b - 12 = 0; b = 12
b + 5 = 0; b = -5
You can't have a negative length so the answer is 12m
To check the answer:
A = (1/2) * 12* 7
A = 42 m^2
Answer:
$2 for 1 rose bush and $2 for one shrub
Step-by-step explanation:
32=2x+14y
26=11x+2y
32=2(2)+14(2)
32=4+28
32=32
26=11(2)+2(2)
26=22+4
26=26
Since both equations come out correct the cost of 1 rose bush is 2 dollars and the cost of one shrub is 2 dollars. kinda cool