Solve 7x − 9 = −23

The solution of 7x − 9 = −23 is x = -2.

7x - 9 = -23\ \Rightarrow\ x = -2

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The lines y = 7x − 9 and y = -23 meet at x = -2. 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.
$7x - 9 = -23$
2
Add 9 to both sides:
$7x - 9 + 9 = -23 + 9 \ \Rightarrow\ 7x = -14$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{-14}{7} \ \Rightarrow\ x = -2$
4
Check: put x = -2 back into the equation.
$7\cdot(-2) - 9 = -14 - 9 = -23 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 9 = -23\ \Rightarrow\ x = -2 \]
\[ 7x - 9 = -23 \]
\[ 7x - 9 + 9 = -23 + 9 \ \Rightarrow\ 7x = -14 \]
\[ \frac{7x}{7} = \frac{-14}{7} \ \Rightarrow\ x = -2 \]
\[ 7\cdot(-2) - 9 = -14 - 9 = -23 \checkmark \]

Trying values of x in 7x − 9 = −23

x	7x − 9	Equals -23?
-4	-37	no
-3	-30	no
-2	-23	yes
-1	-16	no
0	-9	no

Questions

What is x in 7x − 9 = −23?

The solution of 7x − 9 = −23 is x = -2.

How do you solve 7x − 9 = −23?

Add 9 to both sides to get 7x = -14, then divide both sides by 7 to get x = -2.

How do I check the answer?

Replace x by -2: 7(-2) − 9 = -23, which is -23.

Solve 7x − 9 = −23

How to work it out

Trying values of x in 7x − 9 = −23

Questions

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