<span>If f(x)= 5x+40 what is f(x) when x =-5
</span>
---f(x)= 15
Answer:
Step-by-step explanation:
Start by factoring out a -1...
Now, we have to find two integers that multiply to get -16 and have a sum of 6:
(-2)*8=-16
-2+8=8-2=6
Using this, we can split 6x into -2x and 8x...
Factor the first and second half separately...
![f(x)=-[(x^2-2x)+(8x-16)]\\f(x)=-[x(x-2)+8(x-2)]\\](https://tex.z-dn.net/?f=f%28x%29%3D-%5B%28x%5E2-2x%29%2B%288x-16%29%5D%5C%5Cf%28x%29%3D-%5Bx%28x-2%29%2B8%28x-2%29%5D%5C%5C)
Since both x and 8 are being multiplied by x-2, we can combine them to get...
Answer:
q=35
Step-by-step explanation:
x2 - 12x + q = 0
Let the two roots be r and r+2.
Factor the quadratic expression:
(x - r)[x - (r + 2)] = 0
Expand, simplify, group like terms, and get
x2 - 2(r + 1)x + r(r + 2) = 0
Compare to
x2 - 12x + q = 0
and set equal the coefficients of like terms:
Coefficient of x:
-2(r + 1) = -12 ⇒ r + 1 = 6 ⇒ r = 5
(Then the other root is r + 2 = 5 + 2 = 7)
Constant term:
r(r + 2) = q ⇒ 5(5 + 2) = q
q = 35
Test the solution:
(x - 5)(x - 7) = x2 - 12x + 35
With two roots differing by 2, you get an equation of the form
x2 - 12x + q = 0
with q = 35.
Answer:
Decrease
Step-by-step explanation:
160/40 = 4 units/hour
138/36 = 3.833 units/hour
3.833 < 4
So it's a decrease
