ABSOLUTE VALUE:3|x+4|+3=21

[fresh83]

ABSOLUTE VALUE:3|x+4|+3=21

im getting 2 and -12

my steps are

break it up into 2 equations

3(x+4)+3=21

and

3(x+4)+3=-21

distribute and get

3x+12+3=21
3x+12+3=-21

solve

3x=6
3x=-36

 

[stapel]

ABSOLUTE VALUE:3|x+4|+3=21

The solution to any "solving" problem can be checked by plugging it back into the original exercise:

If x = 2, then:

. . . . .3|(2) + 4| + 3 = 3|6| + 3 = 3(6) + 3 = 18 + 3 = 21

If x = -12, then:

. . . . .3|(-12) + 4| + 3 = 3|-8| + 3 = 3(8) + 3 = 24 + 3 = 27

So "x = -12" is clearly not a solution.

To learn, in general, how to solve absolute-value equations, try here.

Then start with isolating the absolute value:

. . . . .3|x + 4| + 3 = 21

. . . . .3|x + 4| = 18

. . . . .|x + 4| = 6

Then split into the two cases:

. . . . .x + 4 = -6
. . . . .x + 4 = 6

Then solve the two linear equations. One will give you the solution you already had. The other will provide a corrected value for the other solution.

:wink: