(I) stands for bars
2007-01-21 10:22:05 · 16 answers · asked by rh 2 in Science & Mathematics ➔ Mathematics
|2x+7|=1
We know that the expression within the absolute value signs can be positive or negative, so let's set up two equations.
2x+7=1 and -2x-7=1
Solve each
2x+7=1
2x= -6
x= -3
-2x-7=1
-2x=8
x= -4
The two answers are x= -3, -4
I hope that this helps.
2007-01-21 10:27:03 · answer #1 · answered by Anonymous · 2⤊ 0⤋
The absolute value of something is defined as the magnitude of the distance of that thing from zero without regard to direction (i.e., in a positive or negative direction). If the absolute value of 2x + 7 is 1, then 2x + 7 is 1 unit from zero, so it is either 1 or -1.
Set 2x+7 = 1 and solve for x; and then set 2x+7 = -1 and solve for x. You will have two possible answers.
Hope that helps.
2007-01-21 18:25:05 · answer #2 · answered by Tim P. 5 · 0⤊ 1⤋
2x + 7 = 1 and 2x + 7 = -1
or
2x= -6 and 2x = -8
x = -3 and x = -4
-3, -4
2007-01-21 19:15:42 · answer #3 · answered by xoxsoccerloverxox 1 · 0⤊ 0⤋
as in "absolute value"?
If so the two roots are:
2x + 7 = 1 and 2x + 7 = -1
or
2x= -6 and 2x = -8
x = -3 and x = -4
-3, -4
2007-01-21 18:26:31 · answer #4 · answered by Anonymous · 1⤊ 0⤋
2x+7=1 2x+7=-1
2x=-6 2x=-8
x=-3 and x=-4
2007-01-21 18:26:41 · answer #5 · answered by Scarecrow 1 · 1⤊ 0⤋
2x+7=1
2x=-6
x=-3
2x+7=-1
2x=-8
x=-4
x=-3 or -4
Check:
I 2(-3)+7 I=1
I -6+7 I=1
I 1 I=1
1=1
I 2(-4)+7 I=1
I -8+7 I=1
I -1 I=1
1=1
I hope this helps!
2007-01-21 18:28:15 · answer #6 · answered by Anonymous · 0⤊ 0⤋
|a| = b
+/-a = b so:
2x+7 = 1
-2x-7 = 1
2x = -6
-2x = 8
x=-3
x=-4
2007-01-21 18:27:19 · answer #7 · answered by Dashes 6 · 1⤊ 0⤋
place -3 into "X" so, it would be [ 2(-3)+7]=1
[-6+7]=1
[1]=1
1=1 <--- your answer.
2007-01-21 18:29:00 · answer #8 · answered by Alex K 1 · 0⤊ 0⤋
2x+7=1
-7 -7
2x= -6
x= negative 3
2007-01-21 18:25:06 · answer #9 · answered by penpal_247 2 · 0⤊ 1⤋
the absolute value of 2x+7 is 1
2x+7=1
2x=-6
x=-3
then 2x+7=-1
2x=-8
x=-4
2007-01-21 18:37:41 · answer #10 · answered by Matt 1 · 0⤊ 0⤋