Solve 4x + 15 = −5

The solution of 4x + 15 = −5 is x = -5.

4x + 15 = -5\ \Rightarrow\ x = -5

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

The lines y = 4x + 15 and y = -5 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 addition, then the multiplication.
$4x + 15 = -5$
2
Subtract 15 from both sides:
$4x + 15 - 15 = -5 - 15 \ \Rightarrow\ 4x = -20$
3
Divide both sides by 4:
$\frac{4x}{4} = \frac{-20}{4} \ \Rightarrow\ x = -5$
4
Check: put x = -5 back into the equation.
$4\cdot(-5) + 15 = -20 + 15 = -5 \checkmark$

LaTeX source of the formulas on this page

\[ 4x + 15 = -5\ \Rightarrow\ x = -5 \]
\[ 4x + 15 = -5 \]
\[ 4x + 15 - 15 = -5 - 15 \ \Rightarrow\ 4x = -20 \]
\[ \frac{4x}{4} = \frac{-20}{4} \ \Rightarrow\ x = -5 \]
\[ 4\cdot(-5) + 15 = -20 + 15 = -5 \checkmark \]

Trying values of x in 4x + 15 = −5

x	4x + 15	Equals -5?
-7	-13	no
-6	-9	no
-5	-5	yes
-4	-1	no
-3	3	no

Questions

What is x in 4x + 15 = −5?

The solution of 4x + 15 = −5 is x = -5.

How do you solve 4x + 15 = −5?

Subtract 15 from both sides to get 4x = -20, then divide both sides by 4 to get x = -5.

How do I check the answer?

Replace x by -5: 4(-5) + 15 = -5, which is -5.

Solve 4x + 15 = −5

How to work it out

Trying values of x in 4x + 15 = −5

Questions

Similar equations