Solve 11x + 12 = −21

The solution of 11x + 12 = −21 is x = -3.

11x + 12 = -21\ \Rightarrow\ x = -3

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The lines y = 11x + 12 and y = -21 meet at x = -3. 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.
$11x + 12 = -21$
2
Subtract 12 from both sides:
$11x + 12 - 12 = -21 - 12 \ \Rightarrow\ 11x = -33$
3
Divide both sides by 11:
$\frac{11x}{11} = \frac{-33}{11} \ \Rightarrow\ x = -3$
4
Check: put x = -3 back into the equation.
$11\cdot(-3) + 12 = -33 + 12 = -21 \checkmark$

LaTeX source of the formulas on this page

\[ 11x + 12 = -21\ \Rightarrow\ x = -3 \]
\[ 11x + 12 = -21 \]
\[ 11x + 12 - 12 = -21 - 12 \ \Rightarrow\ 11x = -33 \]
\[ \frac{11x}{11} = \frac{-33}{11} \ \Rightarrow\ x = -3 \]
\[ 11\cdot(-3) + 12 = -33 + 12 = -21 \checkmark \]

Trying values of x in 11x + 12 = −21

x	11x + 12	Equals -21?
-5	-43	no
-4	-32	no
-3	-21	yes
-2	-10	no
-1	1	no

Questions

What is x in 11x + 12 = −21?

The solution of 11x + 12 = −21 is x = -3.

How do you solve 11x + 12 = −21?

Subtract 12 from both sides to get 11x = -33, then divide both sides by 11 to get x = -3.

How do I check the answer?

Replace x by -3: 11(-3) + 12 = -21, which is -21.

Solve 11x + 12 = −21

How to work it out

Trying values of x in 11x + 12 = −21

Questions

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