Solve 7x − 4 = −18

The solution of 7x − 4 = −18 is x = -2.

7x - 4 = -18\ \Rightarrow\ x = -2

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The lines y = 7x − 4 and y = -18 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.
$7x - 4 = -18$
2
Add 4 to both sides:
$7x - 4 + 4 = -18 + 4 \ \Rightarrow\ 7x = -14$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{-14}{7} \ \Rightarrow\ x = -2$
4
Check: put x = -2 back into the equation.
$7\cdot(-2) - 4 = -14 - 4 = -18 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 4 = -18\ \Rightarrow\ x = -2 \]
\[ 7x - 4 = -18 \]
\[ 7x - 4 + 4 = -18 + 4 \ \Rightarrow\ 7x = -14 \]
\[ \frac{7x}{7} = \frac{-14}{7} \ \Rightarrow\ x = -2 \]
\[ 7\cdot(-2) - 4 = -14 - 4 = -18 \checkmark \]

Trying values of x in 7x − 4 = −18

x	7x − 4	Equals -18?
-4	-32	no
-3	-25	no
-2	-18	yes
-1	-11	no
0	-4	no

Questions

What is x in 7x − 4 = −18?

The solution of 7x − 4 = −18 is x = -2.

How do you solve 7x − 4 = −18?

Add 4 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) − 4 = -18, which is -18.

Solve 7x − 4 = −18

How to work it out

Trying values of x in 7x − 4 = −18

Questions

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