Solve 9x + 15 = −48

The solution of 9x + 15 = −48 is x = -7.

9x + 15 = -48\ \Rightarrow\ x = -7

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

The lines y = 9x + 15 and y = -48 meet at x = -7. 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.
$9x + 15 = -48$
2
Subtract 15 from both sides:
$9x + 15 - 15 = -48 - 15 \ \Rightarrow\ 9x = -63$
3
Divide both sides by 9:
$\frac{9x}{9} = \frac{-63}{9} \ \Rightarrow\ x = -7$
4
Check: put x = -7 back into the equation.
$9\cdot(-7) + 15 = -63 + 15 = -48 \checkmark$

LaTeX source of the formulas on this page

\[ 9x + 15 = -48\ \Rightarrow\ x = -7 \]
\[ 9x + 15 = -48 \]
\[ 9x + 15 - 15 = -48 - 15 \ \Rightarrow\ 9x = -63 \]
\[ \frac{9x}{9} = \frac{-63}{9} \ \Rightarrow\ x = -7 \]
\[ 9\cdot(-7) + 15 = -63 + 15 = -48 \checkmark \]

Trying values of x in 9x + 15 = −48

x	9x + 15	Equals -48?
-9	-66	no
-8	-57	no
-7	-48	yes
-6	-39	no
-5	-30	no

Questions

What is x in 9x + 15 = −48?

The solution of 9x + 15 = −48 is x = -7.

How do you solve 9x + 15 = −48?

Subtract 15 from both sides to get 9x = -63, then divide both sides by 9 to get x = -7.

How do I check the answer?

Replace x by -7: 9(-7) + 15 = -48, which is -48.

Solve 9x + 15 = −48

How to work it out

Trying values of x in 9x + 15 = −48

Questions

Similar equations