Solve 7x − 8 = −43

The solution of 7x − 8 = −43 is x = -5.

7x - 8 = -43\ \Rightarrow\ x = -5

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The lines y = 7x − 8 and y = -43 meet at x = -5. 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.
$7x - 8 = -43$
2
Add 8 to both sides:
$7x - 8 + 8 = -43 + 8 \ \Rightarrow\ 7x = -35$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{-35}{7} \ \Rightarrow\ x = -5$
4
Check: put x = -5 back into the equation.
$7\cdot(-5) - 8 = -35 - 8 = -43 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 8 = -43\ \Rightarrow\ x = -5 \]
\[ 7x - 8 = -43 \]
\[ 7x - 8 + 8 = -43 + 8 \ \Rightarrow\ 7x = -35 \]
\[ \frac{7x}{7} = \frac{-35}{7} \ \Rightarrow\ x = -5 \]
\[ 7\cdot(-5) - 8 = -35 - 8 = -43 \checkmark \]

Trying values of x in 7x − 8 = −43

x	7x − 8	Equals -43?
-7	-57	no
-6	-50	no
-5	-43	yes
-4	-36	no
-3	-29	no

Questions

What is x in 7x − 8 = −43?

The solution of 7x − 8 = −43 is x = -5.

How do you solve 7x − 8 = −43?

Add 8 to both sides to get 7x = -35, then divide both sides by 7 to get x = -5.

How do I check the answer?

Replace x by -5: 7(-5) − 8 = -43, which is -43.

Solve 7x − 8 = −43

How to work it out

Trying values of x in 7x − 8 = −43

Questions

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