Solve 11x + 9 = −90

The solution of 11x + 9 = −90 is x = -9.

11x + 9 = -90\ \Rightarrow\ x = -9

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The lines y = 11x + 9 and y = -90 meet at x = -9. 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.
$11x + 9 = -90$
2
Subtract 9 from both sides:
$11x + 9 - 9 = -90 - 9 \ \Rightarrow\ 11x = -99$
3
Divide both sides by 11:
$\frac{11x}{11} = \frac{-99}{11} \ \Rightarrow\ x = -9$
4
Check: put x = -9 back into the equation.
$11\cdot(-9) + 9 = -99 + 9 = -90 \checkmark$

LaTeX source of the formulas on this page

\[ 11x + 9 = -90\ \Rightarrow\ x = -9 \]
\[ 11x + 9 = -90 \]
\[ 11x + 9 - 9 = -90 - 9 \ \Rightarrow\ 11x = -99 \]
\[ \frac{11x}{11} = \frac{-99}{11} \ \Rightarrow\ x = -9 \]
\[ 11\cdot(-9) + 9 = -99 + 9 = -90 \checkmark \]

Trying values of x in 11x + 9 = −90

x	11x + 9	Equals -90?
-11	-112	no
-10	-101	no
-9	-90	yes
-8	-79	no
-7	-68	no

Questions

What is x in 11x + 9 = −90?

The solution of 11x + 9 = −90 is x = -9.

How do you solve 11x + 9 = −90?

Subtract 9 from both sides to get 11x = -99, then divide both sides by 11 to get x = -9.

How do I check the answer?

Replace x by -9: 11(-9) + 9 = -90, which is -90.

Solve 11x + 9 = −90

How to work it out

Trying values of x in 11x + 9 = −90

Questions

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