Answer:
4x - 12
Step-by-step explanation:
8-4(-x+5)
Distribute
8 - 4*-x -4 * 5
8 +4x - 20
Combine like terms
4x - 12
S = 2*(1/2 * 7 * 14) + 2* (1/2 * 7 * 7) = 7*14 + 7*7 = 7*(14+7) = 7*21 = 147 sm^2
Number B
Answer: 52.94
Step-by-step explanation:
Length of train A = 480m
Tunnel length = 1320m
Time taken to cross tunnel = 2 mins = 120sec
Length of train B = 420m
Train B is slower than train A
Difference between their speed = 18km/hr
18km/hr = (18×1000)/3600 = 5m/s
Speed of train A :
Speed = distance / time
Speed = 1320 / 120 = 11m/s
Therefore, speed of train B :
(11 - 5)m/s = 6m/s
Relative speed of the two trains is therefore;
(Speed of A + speed of B)
Note : they are moving in opposite direction
( 11 + 6)m/s = 17m/s
Therefore time taken to cross each other :
(Sum of the length of both trains / relative speed of the trains)
Time taken = (480m + 420m) / (17m/s)
Time taken = 900m / 17m/s
Time taken = 52.94s
Number 1 and number 3 are the same because if you are purchasing three tires that is 75% off the tires you need and one of them you get free. the free one becomes the overall discount of 25% off. number 3 is the same, the one quarter represents 25% off of the purchase.
Answer:
the total cost would be $45.2
