Solve 12x − 15 = −27

The solution of 12x − 15 = −27 is x = -1.

12x - 15 = -27\ \Rightarrow\ x = -1

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The lines y = 12x − 15 and y = -27 meet at x = -1. 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.
$12x - 15 = -27$
2
Add 15 to both sides:
$12x - 15 + 15 = -27 + 15 \ \Rightarrow\ 12x = -12$
3
Divide both sides by 12:
$\frac{12x}{12} = \frac{-12}{12} \ \Rightarrow\ x = -1$
4
Check: put x = -1 back into the equation.
$12\cdot(-1) - 15 = -12 - 15 = -27 \checkmark$

LaTeX source of the formulas on this page

\[ 12x - 15 = -27\ \Rightarrow\ x = -1 \]
\[ 12x - 15 = -27 \]
\[ 12x - 15 + 15 = -27 + 15 \ \Rightarrow\ 12x = -12 \]
\[ \frac{12x}{12} = \frac{-12}{12} \ \Rightarrow\ x = -1 \]
\[ 12\cdot(-1) - 15 = -12 - 15 = -27 \checkmark \]

Trying values of x in 12x − 15 = −27

x	12x − 15	Equals -27?
-3	-51	no
-2	-39	no
-1	-27	yes
0	-15	no
1	-3	no

Questions

What is x in 12x − 15 = −27?

The solution of 12x − 15 = −27 is x = -1.

How do you solve 12x − 15 = −27?

Add 15 to both sides to get 12x = -12, then divide both sides by 12 to get x = -1.

How do I check the answer?

Replace x by -1: 12(-1) − 15 = -27, which is -27.

Solve 12x − 15 = −27

How to work it out

Trying values of x in 12x − 15 = −27

Questions

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