Answer:
20 mph
Step-by-step explanation:
Let speed of Train a = Va mph
Let speed of Train b = Vb mph
Va = Vb + 30
Let time taken for Train a = Ta
Let time taken for Train b = Tb
time taken = distance travelled/speed
Ta = 350/Va = 350/(Vb+30)
Tb = 140/Vb
But they both travel in the same amount of time.
So, Ta = Tb
Cross multiply
Divide both sides by 210
4x²+4x-35=0
factor: (2x+7)(2x-5)=0
2x+7=0, or 2x-5=0
2x=-7 or 2x=5
x=-3.5 or x=2.5
I don't see any rounding necessary in this case.
when you factor ax²+bx+c, you take the two factors of a and the two factors of c, one factor of a times one factor of c, the other factor of a times the other factors, the sum of the two products make b.
in this case, the factors of 4 is 2 and 2, the factors of -35 is -5 and 7. I line them up in the following way:
2 -5
2 7
then I multiple them diagonally, the top left 2 multiplying the bottom right 7=14, and the other 2 multiplying -5=-10, 14 and -10 make a sum of 4.
if you don't get the desired sum, switch the factors up and down till you have the right combination. Note: Do not switch left and right.
I hope this makes sense to you.
Step-by-step explanation:
Use Pythagorean theorem here. To find the height, find the difference of the 2 y's. To find the length, find the difference between the 2 x's.
Length = x2 - x1
Height = y2 - y1
√length^2 + height^2 = distance
√5^2 + 5^2 = √50 = 7.07
