Please please please help I cannot figure this problem out Car A is traveling east at a steady speed of 60 miles per hour after 2 hours, it is 130 miles east of Johnstown. car B is traveling east on the same road. its distance east of Johnstown is represented by the graph.

45 mph = x

Step-by-step explanation:

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Distance (D) = Rate (R) * Time (T)

For Car  A:  

D = 30T    {Eqn 1}

For Car B:

The Distance D and the time T is the same as for Car A

But, unlike Car A, Car B travels at two different rates.  It travels at 20mph for a time T1.  Then it passes Car A and travels at a rate of x for a period of time T2.

D = (20T1) + (x * T2)

Note that T2 must equal the total time T minus T1, so

D = (20T1) + (x * (T - T1))    {Eqn2}

Substitute Eqn 1 into Enq 2 :   30T = 20T1 + xT - xT1

Rewrite as:  30T = 20T1 + x(T-T1)  {Eqn 3}

At what point do the two cars pass one another?  

Car A travels 30T1  = D1

Car B is traveling in the opposite direction at 20T1 = D2

D2 = D - D1 (where D is the total circular length of the track)

Substituting, 20T1 = D - 30T1.   Or 50T1 = D   {Eqn 4}

Now we can establish a relationship between T and T1 by substituting Eqn1 into Eqn4

D = 30T = 50T1

30T = 50T1

(30/50)T = T1

T1 = (3/5)T   {Eqn 5}

Now substitute Eqn 5 into Eqn 3

30T = 20T1 + x (T-T1)

30T = 20(3/5)T+ x (T - 3/5 T)

30T = 12T +  xT(2/5)

18T = (2/5)x

(5/2)18 = x

45 mph = x

Recall that x is the speed that Car B must travel after it passes Car A.

b.my answer is b.

brainliest

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.