If mary drove 525 miles in 7 hours at an average speed of 75 miles per hour, how fast would her average speed need to be to make the trip in 5 hours (a little speed

525/5 = 105 miles per hour for the speed demon.

Well it was quite simple to answer this question. As we knew the total distance that the speed demon had to cover in a specific amount of time that is obviously 5 hours we can simply divide the total distance by the time we had to travel.

Other wise obviously we could have calculated the average speeds separately and could have done it in a different manner.

system of linear equation

step-by-step explanation:

as given in the data

a= 20 , b= -12

let us suppose that it is a straight line equation

now we know the formula for the system of linear equation

b= ma + c )

here m is slope of a straight line which is equal to formula

m=   (ii)

and here c is a constant

now putting the value of a and b in equation (ii)

m=

m=

putting the value of a,b and m in equation (i) gives us

-12 = + c

-12=-12 + c

adding 12 to both sides

-12 +12 = -12 +12 +c

0 =c

or c=0

as the value of the constant is zero which gives us that it is a linear equation and this order pair satisfies the system of linear equations.