31. It gives you the equation f(x) = -2x + 4 and asks you to solve for f(12). To solve this you must replace x in the equation -2x + 4 with 12 like so:
-2(12) + 4
Remember that when solving this use your rules of PEMDAS. In this case you will first multiply -2 and 12 then add the product with 4
-24 + 4
f(12) = -20
33. Replace x in the equation x³ - x with 5 like so...
5³ - 5
Again, remember to use the rules of PEMDAS to solve this. First take the cube of 5 then subtract 5 from the answer
125 - 5
g(5) = 120
Hope this helped!
~Just a girl in love with Shawn Mendes
A plane flew 193 km in 12 minutes at constant speed. what was the speed of the airplane in km per hour? "965 km'
Answer:
Therefore the value of y(1)= 0.9152.
Step-by-step explanation:
According to the Euler's method
y(x+h)≈ y(x) + hy'(x) ....(1)
Given that y(0) =3 and step size (h) = 0.2.

Putting the value of y'(x) in equation (1)

Substituting x =0 and h= 0.2
![y(0+0.2)\approx y(0)+0.2[0\times y(0)-\frac12 (y(0))^2]](https://tex.z-dn.net/?f=y%280%2B0.2%29%5Capprox%20y%280%29%2B0.2%5B0%5Ctimes%20y%280%29-%5Cfrac12%20%28y%280%29%29%5E2%5D)
[∵ y(0) =3 ]

Substituting x =0.2 and h= 0.2
![y(0.2+0.2)\approx y(0.2)+0.2[(0.2)^2\times y(0.2)-\frac12 (y(0.2))^2]](https://tex.z-dn.net/?f=y%280.2%2B0.2%29%5Capprox%20y%280.2%29%2B0.2%5B%280.2%29%5E2%5Ctimes%20y%280.2%29-%5Cfrac12%20%28y%280.2%29%29%5E2%5D)
![\Rightarrow y(0.4)\approx 2.7+0.2[(0.2)^2\times 2.7- \frac12(2.7)^2]](https://tex.z-dn.net/?f=%5CRightarrow%20y%280.4%29%5Capprox%20%202.7%2B0.2%5B%280.2%29%5E2%5Ctimes%202.7-%20%5Cfrac12%282.7%29%5E2%5D)

Substituting x =0.4 and h= 0.2
![y(0.4+0.2)\approx y(0.4)+0.2[(0.4)^2\times y(0.4)-\frac12 (y(0.4))^2]](https://tex.z-dn.net/?f=y%280.4%2B0.2%29%5Capprox%20y%280.4%29%2B0.2%5B%280.4%29%5E2%5Ctimes%20y%280.4%29-%5Cfrac12%20%28y%280.4%29%29%5E2%5D)
![\Rightarrow y(0.6)\approx 1.9926+0.2[(0.4)^2\times 1.9926- \frac12(1.9926)^2]](https://tex.z-dn.net/?f=%5CRightarrow%20y%280.6%29%5Capprox%20%201.9926%2B0.2%5B%280.4%29%5E2%5Ctimes%201.9926-%20%5Cfrac12%281.9926%29%5E2%5D)

Substituting x =0.6 and h= 0.2
![y(0.6+0.2)\approx y(0.6)+0.2[(0.6)^2\times y(0.6)-\frac12 (y(0.6))^2]](https://tex.z-dn.net/?f=y%280.6%2B0.2%29%5Capprox%20y%280.6%29%2B0.2%5B%280.6%29%5E2%5Ctimes%20y%280.6%29-%5Cfrac12%20%28y%280.6%29%29%5E2%5D)
![\Rightarrow y(0.8)\approx 1.6593+0.2[(0.6)^2\times 1.6593- \frac12(1.6593)^2]](https://tex.z-dn.net/?f=%5CRightarrow%20y%280.8%29%5Capprox%20%201.6593%2B0.2%5B%280.6%29%5E2%5Ctimes%201.6593-%20%5Cfrac12%281.6593%29%5E2%5D)

Substituting x =0.8 and h= 0.2
![y(0.8+0.2)\approx y(0.8)+0.2[(0.8)^2\times y(0.8)-\frac12 (y(0.8))^2]](https://tex.z-dn.net/?f=y%280.8%2B0.2%29%5Capprox%20y%280.8%29%2B0.2%5B%280.8%29%5E2%5Ctimes%20y%280.8%29-%5Cfrac12%20%28y%280.8%29%29%5E2%5D)
![\Rightarrow y(1.0)\approx 0.8800+0.2[(0.8)^2\times 0.8800- \frac12(0.8800)^2]](https://tex.z-dn.net/?f=%5CRightarrow%20y%281.0%29%5Capprox%20%200.8800%2B0.2%5B%280.8%29%5E2%5Ctimes%200.8800-%20%5Cfrac12%280.8800%29%5E2%5D)

Therefore the value of y(1)= 0.9152.
Answer:
(Choice B) B It decreases.
Step-by-step explanation:
According to the situation, the solution of the value of the expression is as follows
Let us assume
r 80 -2r
5 80 - 10 = 70
4 80 - 8 = 72
3 80 - 6 = 74
2 80 - 4 = 76
1 80 - 2 = 78
As we can from the above calculation that expression value risen if r value decreased
Therefore the correct option is B.