Solve for varible "x"

G

Guest

Guest
WHAT HAVE I DONE WRONG IN THIS PROBLEM? I GOT THE ANSWER OF -3 WHEN IT SHOULD BE 3.

Problem:
Gary, Barry and Terry belong to a car club. Gary’s car is, five times as old as Barry’s car, and Terry’s car is, six years younger than Gary’s. In three years, the age of Terry’s car will be twice the age of Barry’s. How old is Gary’s car now?

Code:
          GARY      BARRY      TERRY
Now:       5x         x        5x – 6
Later:   5x + 3     x + 3     2(x + 3)
x + 3 = 2(x + 3)

x + 3 = 2x + 6

subtract -3 from both sides

1x = 2x + 3

subtract -2x from both sides

-1x = 3
Divide both sides by -1

x = -3 THAT'S NOT RIGHT
 

sagar1127

New member
Joined
Mar 27, 2006
Messages
20
you multiplied 3 also when it is not supposed to be changed


what you did is made terry's car in 6 instead of 3 [...=2(x+3)]

it supposed to be 2x+3
 

stapel

Super Moderator
Staff member
Joined
Feb 4, 2004
Messages
15,943
You're sooooo close! :D

Replace the "2(x + 3)" at the end of the last row with "(5x - 6) + 3". Simplify.

Then translate the following:

. . . . .(Terry's later value) is (twice) (Barry's later value)

...into an equation. Solve.

Eliz.
 
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