25 = 30
20 = 4x-4
(25)(4x-4) = (20)(30)
100x - 100 = 600
100x = 600 + 100
100x = 700
x = 7
Hope it helps!
Face Paint?..? Because when he retires maybe he wants people to know hes there? Idk im sorry.
Answer:
- KEi = 2.256×10^5 J
- KEf = 9.023×10^5 J
- 4 times as much work
Step-by-step explanation:
The kinetic energy for a given mass and velocity is ...
KE = (1/2)mv^2 . . . . . m is mass
At its initial speed, the kinetic energy of the car is ...
KEi = (1/2)(810 kg)(23.6 m/s)^2 ≈ 2.256×10^5 J . . . . . m is meters
At its final speed, the kinetic energy of the car is ...
KEf = (1/2)(810 kg)(47.2 m/s)^2 ≈ 9.023×10^5 J
The ratio of final to initial kinetic energy is ...
(9.023×10^5)/(2.256×10^5) = 4
4 times as much work must be done to stop the car.
_____
You know this without computing the kinetic energy. KE is proportional to the square of speed, so when the speed doubles, the KE is multiplied by 2^2 = 4.
3x-4y-8=12
first combine like terms
3x-4y=12+8
then isolate on variable
3x=20+4y
now divide by three to find x
x=20/3+4/3 x=8
to find y plug in x to the original equation
3(8)-4y-8=12
24-4y=20
-4y=20-24
-4y=-4
y=1