Given (21,7) and (x,
1), find all x such that the distance between these two points is 17.

21+/-sqrt(253)=x

So one value for x is 21+sqrt(253)

and another is 21-sqrt(253)

Problem:

Given (21,7) and (x,1), find all x such that the distance between these two points is 17.

Step-by-step explanation:

Change in x is x-21

Change in y is 7-1=6

distance^2=(change in x)^2+(change in y)^2

17^2=(x-21)^2+(6)^2

289=(x-21)^2+36

Subtract 36 on both sides:

289-36=(x-21)^2

253=(x-21)^2

Take square root of both sides:

+/-sqrt(253)=x-21

Add 21 on both sides:

21+/-sqrt(253)=x

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

eventually after a few more steps, your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x

you save $70

discount would be 35% off

step-by-step explanation: