Answer:
Let the speed of the train be x km/h.
Case 1:
Distance = 288 km
Speed = x km/h
Time = Distance/Speed
= 288/x h
Case 2:
Distance = 288 km
Speed = (x+4) km/h
Time = 288/x + 4 h
Since 288/x > 288/x + 4
288/x - 288/x+4 = 1
288[1/x - 1/x+4 ] = 1
[ x + 4 - x / x(x + 4) ] = 1/288
[4 / x^2 + 4x ] = 1/288
x^2 + 4x = 1152
x^2 + 4x - 1152 = 0
x^2 + 36x - 32x - 1152 = 0
x(x + 36) - 32(x + 36) = 0
(x + 36)(x - 32) = 0
x + 36 = 0 , x - 32 = 0
x = -36 , x = 32
x = -36 , rejected since speed cannot be negative.
Therefore , speed of the train = 32 km/h
Answer:
4) -4
5) -6x-20
Step-by-step explanation:
Add x with x's and numbers with numbers
4) -6x + 9 + 6x -13
-6x+6x+9-13
x's cancel
9-13 = -4
5) 8x - 9 -11 -14x
8x-14x-9-11
-6x-20
hope this helps
124 - 78 = 46.....Harrison used 46 more blocks then Greyson
PR=18mm
AB=7mm
All lengths of triangle PRQ are twice the lengths of ACB
D' = (-2, 0) = 2*(-1, 0) = 2*D
The scale factor is 2.
