You have to find first the discriminant
∆=8^2-4*(-1) *(-7) =36
x=(-8±√36) /-2=(-8±6)/-2=4±3=1 or 7
So x(1)=1 or x(2)=7
-x^2+8x-7=[x-x(1) ][x-x(2) ]=(x-1) (x-7)
Answer:
156 [in²].
Step-by-step explanation:
1) total area consists of six parts (all the details are in the attachment):
A=2A₁+2A₂+A₃+A₄;
2) according to the formula above:
A=2*5*3+2*0.5*(6+12)*4+6*3+12*3=156 [in²].
Answer:
B, Seth lost $261 by selling stocks.
Step-by-step explanation:
Since the income is negative, it would only be logical that he would've lost money, since you can't make negative money.
Let W = number of white cars, and Y = number of yellow cars.
There were 9 times as many white cars as yellow cars. This means that the number of white cars was 9 times more than the number of yellow cars. This can be translated by the expression:
9Y = W
The person counted 40 cars in total:
W + Y = 40
So we get the system:

In the first equation, we multiply by 9:
9W + 9Y = 360
In the second equation:
9Y= W
W-9Y = 0
Then we add the first with the second equation:
9W + 9Y + W - 9Y = 360
10 W = 360
W = 36
So He counted 36 white cars.
Hope this Helps! :)