How do you solve abs(7-2x)=5|72x|=5?

2 Answers
Aug 26, 2017

x= 1 and 6x=1and6

Explanation:

The use of the special brackets of | | means that whatever is inside them is considered as positive.

On the right side of the equals we have +5.

So the left side must end up as |+-5||±5| giving:

|+-5|=+5|±5|=+5

Ok!

Lets consider what will turn 7-2x72x into -5

Set color(white)("d")7-2x=-5d72x=5

2x=7+52x=7+5

x=12/2=+6x=122=+6

Check (color(white)(2/2)7-[2xx6]color(white)("d") ) -> 7-12 = -5(227[2×6]d)712=5 as required

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Lets consider what will turn 7-2x72x into +5

Set color(white)("d")7-2x=+5d72x=+5

2x=7-52x=75

x=2/2=1x=22=1

Check (color(white)(2/2)7-[2xx1]color(white)("d")) -> 5xx1=+5(227[2×1]d)5×1=+5 as required

Aug 26, 2017

See a solution process below:

Explanation:

The absolute value function takes any term and transforms it to its non-negative form. Therefore, we must solve the term within the absolute value function for both its negative and positive equivalent.

Solution 1

7 - 2x = -572x=5

-color(red)(7) + 7 - 2x = -color(red)(7) - 57+72x=75

0 - 2x = -1202x=12

-2x = -122x=12

(-2x)/color(red)(-2) = (-12)/color(red)(-2)2x2=122

(color(red)(cancel(color(black)(-2)))x)/cancel(color(red)(-2)) = 6

x = 6

Solution 2

7 - 2x = 5

-color(red)(7) + 7 - 2x = -color(red)(7) + 5

0 - 2x = -2

-2x = -2

(-2x)/color(red)(-2) = (-2)/color(red)(-2)

(color(red)(cancel(color(black)(-2)))x)/cancel(color(red)(-2)) = 1

x = 1

The Solutions Are: x = 6 and x = 1