Solve 12x − 1 = −121

The solution of 12x − 1 = −121 is x = -10.

12x - 1 = -121\ \Rightarrow\ x = -10

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The lines y = 12x − 1 and y = -121 meet at x = -10. 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.
$12x - 1 = -121$
2
Add 1 to both sides:
$12x - 1 + 1 = -121 + 1 \ \Rightarrow\ 12x = -120$
3
Divide both sides by 12:
$\frac{12x}{12} = \frac{-120}{12} \ \Rightarrow\ x = -10$
4
Check: put x = -10 back into the equation.
$12\cdot(-10) - 1 = -120 - 1 = -121 \checkmark$

LaTeX source of the formulas on this page

\[ 12x - 1 = -121\ \Rightarrow\ x = -10 \]
\[ 12x - 1 = -121 \]
\[ 12x - 1 + 1 = -121 + 1 \ \Rightarrow\ 12x = -120 \]
\[ \frac{12x}{12} = \frac{-120}{12} \ \Rightarrow\ x = -10 \]
\[ 12\cdot(-10) - 1 = -120 - 1 = -121 \checkmark \]

Trying values of x in 12x − 1 = −121

x	12x − 1	Equals -121?
-12	-145	no
-11	-133	no
-10	-121	yes
-9	-109	no
-8	-97	no

Questions

What is x in 12x − 1 = −121?

The solution of 12x − 1 = −121 is x = -10.

How do you solve 12x − 1 = −121?

Add 1 to both sides to get 12x = -120, then divide both sides by 12 to get x = -10.

How do I check the answer?

Replace x by -10: 12(-10) − 1 = -121, which is -121.

Solve 12x − 1 = −121

How to work it out

Trying values of x in 12x − 1 = −121

Questions

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