If alexandra increases her usual driving speed by 15 km/h, it will take her 2 hours less to make a trip to her gradnparents house. If she decreaseshe rusualy speed by 15 km/h, it will take her 3 h more than usualy to make the trip. How long is the trip?

Therefore,

Distance of the trip is

Step-by-step explanation:

Let "x" be the Speed of the car and,

"y" be the time to cover the trip to her grandparents,

To Find:

How long is the trip = ?

Solution:

We Know that,

According to the First given condition,

According to the Second given condition,

As we  know Distance will remain same so we have

Substituting the values we get

So on  Substituting we have

..............Equation ( 1)

Again on  Substituting we have

...........Equation ( 2)

Subtracting Equation 1 from equation 2 we get

Substitute y = 12 in equation 1 we get

So we have now,

Therefore the Distance of the trip is

Therefore,

Distance of the trip is

to determine the unit cost your would divide the total cost by the number sold.

7 bagels for $4.41       $4.41/7 = $.63 each at fresh side

5 bagels for $3.60         $3.60/5 = $.72 each at value mart