Solve 2x + 9 = −3

The solution of 2x + 9 = −3 is x = -6.

2x + 9 = -3\ \Rightarrow\ x = -6

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The lines y = 2x + 9 and y = -3 meet at x = -6. The solution of the equation is the x-coordinate of the point where the two sides are equal.

How to work it out

1
The goal is to get x alone. Undo the operations in the opposite order: first the addition, then the multiplication.
$2x + 9 = -3$
2
Subtract 9 from both sides:
$2x + 9 - 9 = -3 - 9 \ \Rightarrow\ 2x = -12$
3
Divide both sides by 2:
$\frac{2x}{2} = \frac{-12}{2} \ \Rightarrow\ x = -6$
4
Check: put x = -6 back into the equation.
$2\cdot(-6) + 9 = -12 + 9 = -3 \checkmark$

LaTeX source of the formulas on this page

\[ 2x + 9 = -3\ \Rightarrow\ x = -6 \]
\[ 2x + 9 = -3 \]
\[ 2x + 9 - 9 = -3 - 9 \ \Rightarrow\ 2x = -12 \]
\[ \frac{2x}{2} = \frac{-12}{2} \ \Rightarrow\ x = -6 \]
\[ 2\cdot(-6) + 9 = -12 + 9 = -3 \checkmark \]

Trying values of x in 2x + 9 = −3

x	2x + 9	Equals -3?
-8	-7	no
-7	-5	no
-6	-3	yes
-5	-1	no
-4	1	no

Questions

What is x in 2x + 9 = −3?

The solution of 2x + 9 = −3 is x = -6.

How do you solve 2x + 9 = −3?

Subtract 9 from both sides to get 2x = -12, then divide both sides by 2 to get x = -6.

How do I check the answer?

Replace x by -6: 2(-6) + 9 = -3, which is -3.

Solve 2x + 9 = −3

How to work it out

Trying values of x in 2x + 9 = −3

Questions

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