Solve 12x + 3 = −69

The solution of 12x + 3 = −69 is x = -6.

12x + 3 = -69\ \Rightarrow\ x = -6

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The lines y = 12x + 3 and y = -69 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.
$12x + 3 = -69$
2
Subtract 3 from both sides:
$12x + 3 - 3 = -69 - 3 \ \Rightarrow\ 12x = -72$
3
Divide both sides by 12:
$\frac{12x}{12} = \frac{-72}{12} \ \Rightarrow\ x = -6$
4
Check: put x = -6 back into the equation.
$12\cdot(-6) + 3 = -72 + 3 = -69 \checkmark$

LaTeX source of the formulas on this page

\[ 12x + 3 = -69\ \Rightarrow\ x = -6 \]
\[ 12x + 3 = -69 \]
\[ 12x + 3 - 3 = -69 - 3 \ \Rightarrow\ 12x = -72 \]
\[ \frac{12x}{12} = \frac{-72}{12} \ \Rightarrow\ x = -6 \]
\[ 12\cdot(-6) + 3 = -72 + 3 = -69 \checkmark \]

Trying values of x in 12x + 3 = −69

x	12x + 3	Equals -69?
-8	-93	no
-7	-81	no
-6	-69	yes
-5	-57	no
-4	-45	no

Questions

What is x in 12x + 3 = −69?

The solution of 12x + 3 = −69 is x = -6.

How do you solve 12x + 3 = −69?

Subtract 3 from both sides to get 12x = -72, then divide both sides by 12 to get x = -6.

How do I check the answer?

Replace x by -6: 12(-6) + 3 = -69, which is -69.

Solve 12x + 3 = −69

How to work it out

Trying values of x in 12x + 3 = −69

Questions

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