Solve 11x − 12 = −78

The solution of 11x − 12 = −78 is x = -6.

11x - 12 = -78\ \Rightarrow\ x = -6

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The lines y = 11x − 12 and y = -78 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 subtraction, then the multiplication.
$11x - 12 = -78$
2
Add 12 to both sides:
$11x - 12 + 12 = -78 + 12 \ \Rightarrow\ 11x = -66$
3
Divide both sides by 11:
$\frac{11x}{11} = \frac{-66}{11} \ \Rightarrow\ x = -6$
4
Check: put x = -6 back into the equation.
$11\cdot(-6) - 12 = -66 - 12 = -78 \checkmark$

LaTeX source of the formulas on this page

\[ 11x - 12 = -78\ \Rightarrow\ x = -6 \]
\[ 11x - 12 = -78 \]
\[ 11x - 12 + 12 = -78 + 12 \ \Rightarrow\ 11x = -66 \]
\[ \frac{11x}{11} = \frac{-66}{11} \ \Rightarrow\ x = -6 \]
\[ 11\cdot(-6) - 12 = -66 - 12 = -78 \checkmark \]

Trying values of x in 11x − 12 = −78

x	11x − 12	Equals -78?
-8	-100	no
-7	-89	no
-6	-78	yes
-5	-67	no
-4	-56	no

Questions

What is x in 11x − 12 = −78?

The solution of 11x − 12 = −78 is x = -6.

How do you solve 11x − 12 = −78?

Add 12 to both sides to get 11x = -66, then divide both sides by 11 to get x = -6.

How do I check the answer?

Replace x by -6: 11(-6) − 12 = -78, which is -78.

Solve 11x − 12 = −78

How to work it out

Trying values of x in 11x − 12 = −78

Questions

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