Heather left the hospital and drove toward the desert at an average speed of 35 km/h. danielle left sometime later driving in the opposite direction with an average speed of 50 km/h. after heather had driven for four hours they were 290 km apart. how long did danielle

Danielle drove 3 hours

Step-by-step explanation:

Suppose Heather moved in the x direction.

Then Danielle moved in the opposite direction, that is, she moved in the -x direction.

Let's call , , at the speed, distance and time that I code Heather

Let's call , , at the speed, distance and time Danielle codes.

Observe the following diagram:

(x) Heather <------ --------- hospital ---------- -----------> Danielle (-x)

So:

We know that after 4 hours the distance between Heather and Danielle was 290 km.

That is to say:

We know that

We already know , the distance from the hospital to Heather, so we can find and thus know

So:

Then:

Danielle travelled for 3 hours

Distance travelled by Danielle: 150km

Step-by-step explanation:

We are asked to find out the time that Danielle travelled and the distance travelled by her.

Average Speed of Heather, v = 35 km/hr

Time that Heather travelled, t = 4hr

Distance travelled by Heather, s(heather) = v * t = 35 * 4 = 140 km

Now we are also given the total distance travelled by them which is 290 km

Total Distance, s(total) = 290km

Distance travelled by Danielle would be equal to Total distance minus Distane travelled by Heather

s(Danielle) = s(total) - s(heather)

                  = 290 - 140 = 150 km

Time travelled by Danielle would be calculated then:

Speed of Danielle = 50 km/hr

t =

c: y > - 1/6x + 1

step-by-step explanation:

dashed line - meaning this < or > also not equal

solid line - meaning this < or > also equal

your answer is c because y > means up & it's shaded up, but y < means down

hope this ! : )