Solve 9x + 7 = −20

The solution of 9x + 7 = −20 is x = -3.

9x + 7 = -20\ \Rightarrow\ x = -3

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

The lines y = 9x + 7 and y = -20 meet at x = -3. 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.
$9x + 7 = -20$
2
Subtract 7 from both sides:
$9x + 7 - 7 = -20 - 7 \ \Rightarrow\ 9x = -27$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{-27}{9} \ \Rightarrow\ x = -3$
4
Check: put x = -3 back into the equation.
$9\cdot(-3) + 7 = -27 + 7 = -20 \checkmark$

LaTeX source of the formulas on this page

\[ 9x + 7 = -20\ \Rightarrow\ x = -3 \]
\[ 9x + 7 = -20 \]
\[ 9x + 7 - 7 = -20 - 7 \ \Rightarrow\ 9x = -27 \]
\[ \frac{9x}{9} = \frac{-27}{9} \ \Rightarrow\ x = -3 \]
\[ 9\cdot(-3) + 7 = -27 + 7 = -20 \checkmark \]

Trying values of x in 9x + 7 = −20

x	9x + 7	Equals -20?
-5	-38	no
-4	-29	no
-3	-20	yes
-2	-11	no
-1	-2	no

Questions

What is x in 9x + 7 = −20?

The solution of 9x + 7 = −20 is x = -3.

How do you solve 9x + 7 = −20?

Subtract 7 from both sides to get 9x = -27, then divide both sides by 9 to get x = -3.

How do I check the answer?

Replace x by -3: 9(-3) + 7 = -20, which is -20.

Solve 9x + 7 = −20

How to work it out

Trying values of x in 9x + 7 = −20

Questions

Similar equations