Solve 7x + 9 = −47

The solution of 7x + 9 = −47 is x = -8.

7x + 9 = -47\ \Rightarrow\ x = -8

Explain it step by step in chat Make a short video of it

The lines y = 7x + 9 and y = -47 meet at x = -8. 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.
$7x + 9 = -47$
2
Subtract 9 from both sides:
$7x + 9 - 9 = -47 - 9 \ \Rightarrow\ 7x = -56$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{-56}{7} \ \Rightarrow\ x = -8$
4
Check: put x = -8 back into the equation.
$7\cdot(-8) + 9 = -56 + 9 = -47 \checkmark$

LaTeX source of the formulas on this page

\[ 7x + 9 = -47\ \Rightarrow\ x = -8 \]
\[ 7x + 9 = -47 \]
\[ 7x + 9 - 9 = -47 - 9 \ \Rightarrow\ 7x = -56 \]
\[ \frac{7x}{7} = \frac{-56}{7} \ \Rightarrow\ x = -8 \]
\[ 7\cdot(-8) + 9 = -56 + 9 = -47 \checkmark \]

Trying values of x in 7x + 9 = −47

x	7x + 9	Equals -47?
-10	-61	no
-9	-54	no
-8	-47	yes
-7	-40	no
-6	-33	no

Questions

What is x in 7x + 9 = −47?

The solution of 7x + 9 = −47 is x = -8.

How do you solve 7x + 9 = −47?

Subtract 9 from both sides to get 7x = -56, then divide both sides by 7 to get x = -8.

How do I check the answer?

Replace x by -8: 7(-8) + 9 = -47, which is -47.

Solve 7x + 9 = −47

How to work it out

Trying values of x in 7x + 9 = −47

Questions

Similar equations