Solve 10x + 8 = −42

The solution of 10x + 8 = −42 is x = -5.

10x + 8 = -42\ \Rightarrow\ x = -5

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

The lines y = 10x + 8 and y = -42 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.
$10x + 8 = -42$
2
Subtract 8 from both sides:
$10x + 8 - 8 = -42 - 8 \ \Rightarrow\ 10x = -50$
3
Divide both sides by 10:
$\frac{10x}{10} = \frac{-50}{10} \ \Rightarrow\ x = -5$
4
Check: put x = -5 back into the equation.
$10\cdot(-5) + 8 = -50 + 8 = -42 \checkmark$

LaTeX source of the formulas on this page

\[ 10x + 8 = -42\ \Rightarrow\ x = -5 \]
\[ 10x + 8 = -42 \]
\[ 10x + 8 - 8 = -42 - 8 \ \Rightarrow\ 10x = -50 \]
\[ \frac{10x}{10} = \frac{-50}{10} \ \Rightarrow\ x = -5 \]
\[ 10\cdot(-5) + 8 = -50 + 8 = -42 \checkmark \]

Trying values of x in 10x + 8 = −42

x	10x + 8	Equals -42?
-7	-62	no
-6	-52	no
-5	-42	yes
-4	-32	no
-3	-22	no

Questions

What is x in 10x + 8 = −42?

The solution of 10x + 8 = −42 is x = -5.

How do you solve 10x + 8 = −42?

Subtract 8 from both sides to get 10x = -50, then divide both sides by 10 to get x = -5.

How do I check the answer?

Replace x by -5: 10(-5) + 8 = -42, which is -42.

Solve 10x + 8 = −42

How to work it out

Trying values of x in 10x + 8 = −42

Questions

Similar equations