Solve 12x − 6 = −90

The solution of 12x − 6 = −90 is x = -7.

12x - 6 = -90\ \Rightarrow\ x = -7

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The lines y = 12x − 6 and y = -90 meet at x = -7. 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 subtraction, then the multiplication.
$12x - 6 = -90$
2
Add 6 to both sides:
$12x - 6 + 6 = -90 + 6 \ \Rightarrow\ 12x = -84$
3
Divide both sides by 12:
$\frac{12x}{12} = \frac{-84}{12} \ \Rightarrow\ x = -7$
4
Check: put x = -7 back into the equation.
$12\cdot(-7) - 6 = -84 - 6 = -90 \checkmark$

LaTeX source of the formulas on this page

\[ 12x - 6 = -90\ \Rightarrow\ x = -7 \]
\[ 12x - 6 = -90 \]
\[ 12x - 6 + 6 = -90 + 6 \ \Rightarrow\ 12x = -84 \]
\[ \frac{12x}{12} = \frac{-84}{12} \ \Rightarrow\ x = -7 \]
\[ 12\cdot(-7) - 6 = -84 - 6 = -90 \checkmark \]

Trying values of x in 12x − 6 = −90

x	12x − 6	Equals -90?
-9	-114	no
-8	-102	no
-7	-90	yes
-6	-78	no
-5	-66	no

Questions

What is x in 12x − 6 = −90?

The solution of 12x − 6 = −90 is x = -7.

How do you solve 12x − 6 = −90?

Add 6 to both sides to get 12x = -84, then divide both sides by 12 to get x = -7.

How do I check the answer?

Replace x by -7: 12(-7) − 6 = -90, which is -90.

Solve 12x − 6 = −90

How to work it out

Trying values of x in 12x − 6 = −90

Questions

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