Question

solve each absolute value equation:
I 2x-5 I=I 9x+7 I

Answer 1

solve the following two equations
\[2x-5=9x+7\] and \[2x-5=-9x-7\] and get two answers

Answer 2

is the answer -12/7=X and 12/7? This is what I came up with...

Answer 3

also, why wouldn't the 'and' be 'or'?

Answer 4

one is right, the \(-\frac{12}{7}\) is correct

Answer 5

well in math, yes, the answer would be "this number or that number" for sure
but in english i think it is more idiomatic to say solve this equation and that equation

Answer 6

if you say "solve this equation "or" that equation it sounds like you are given a choice of which to solve. you can have the soup or salad

Answer 7

true and I'd rather it say that since I'm not a math expert by all means ;) so the right side is not 12/7=X? I'm doing something incorrect then...

Answer 8

@hills
is the answer -12/7=X and 12/7? This is what I came up with...
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I'm getting -12/7 = X or -2/11 = X.
From Sat's second equation,
2x - 5 = -9x - 7
11x = -2
x = -2/11

Answer 9

Directrix, I came up with 2/11 on the left side and -12/11 on the right side. Does this matter? I worked the problem from left to right...

Answer 10

I meant -12/7 on the right side.

Answer 11

See if you agree with the following:
2x - 5 = -9x - 7
2x + 9x = -7 + 5
11x = -2
x = -2/11

and also

2x - 5 = 9x + 7
2x - 9x = 7 + 5
-7x = 12
x = - 12/7

Answer 12

It looks exact except for I'm confused why both would be negative answers. I just have a hard time with the negative and positives. I realize that two negatives make a positive...

Answer 13

So how would I check my solution?

Answer 14

@hills Because the values of x are negative does not mean that either of I 2x-5 I and
I 9x+7 I will be negative.
I'll check x = -2/11 and you can check the other answer. Okay?
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x = -2/11
Check against I 2x-5 I=I 9x+7 I

I (2(-2/11) -5) I = I( 9(-2/11) +7) I ??
I( -4/11 - 5) I=I( -18/11 +7) I ??
I( -4/11 - 55/11) I = I (-18/11 +77/11) I ??
I (-59/11) I = I (59/11) I ??
59/11 = 59/11
Answer of x = -2/11 is correct

Answer 15

Okay, thanks I will try checking the other answer and show what I come with...