3|2x+5|-9 = 0 solve the absolute value equation

x=−1 or x=−4

Step-by-step explanation:

Let's solve your equation step-by-step.

3(|2x+5|)−9=0

Step 1: Add 9 to both sides.

3(|2x+5|)−9+9=0+9

3(|2x+5|)=9

Step 2: Divide both sides by 3.

3(|2x+5|)

3

=

9

3

|2x+5|=3

Step 3: Solve Absolute Value.

|2x+5|=3

We know either2x+5=3or2x+5=−3

2x+5=3(Possibility 1)

2x+5−5=3−5(Subtract 5 from both sides)

2x=−2

2x

2

=

−2

2

(Divide both sides by 2)

x=−1

2x+5=−3(Possibility 2)

2x+5−5=−3−5(Subtract 5 from both sides)

2x=−8

2x

2

=

−8

2

(Divide both sides by 2)

x=−4

x=−1 or x=−4

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18