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1 vote
2 l2x+7l = 16
Please help me with this ASAP

User Myndex
by
4.5k points

2 Answers

4 votes

Answer:

x = -
(15)/(2) , x =
(1)/(2)

Explanation:

2 | 2x + 7 | = 16 ( divide both sides by 2 )

| 2x + 7 | = 8

the absolute value function always gives a positive result, but the expression inside can be positive or negative , that is

2x + 7 = 8 ( subtract 7 from both sides )

2x = 1 ( divide both sides by 2 )

x =
(1)/(2)

or

- (2x + 7) = 8

- 2x - 7 = 8 ( add 7 to both sides )

- 2x = 15 ( divide both sides by - 2 )

x = -
(15)/(2)

As a check

substitute these values into the left side and if equal to the right side then they are a solution

x =
(1)/(2)

2 | 2(
(1)/(2) ) + 7 | = 2 | 1 + 7 | = 2 | 8 | = 16 = right side

x = -
(15)/(2)

2 | 2(-
(15)/(2) ) + 7 | = 2 | - 15 + 7 | = 2 | - 8 | = 2 | 8 | = 16 = right side

then x = -
(15)/(2) and x =
(1)/(2) are the solutions

User Goni
by
5.4k points
6 votes

Answer:

x = 1/2 and

x = -15/2

Explanation:

First, get the absolute value alone on one side if the equation.

2 |2x + 7 | = 16

Divide both sides by 2.

| 2x + 7 | = 8

Once the absolute value sign is by itself, you will separate the equation into two separate equations.

2x+7=8 and 2x+7=-8

Solve these two equations separately and get two solutions.

2x + 7 = 8

Subtract 7.

2x = 1

Divide by 2.

x = 1/2 Here is one solution.

2x + 7 = -8

Subtract 7.

2x = -15

Divide by 2.

x = -15/2 Here is a second solution.

User Odino
by
5.0k points