Solve 8x + 3 = −77

The solution of 8x + 3 = −77 is x = -10.

8x + 3 = -77\ \Rightarrow\ x = -10

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

The lines y = 8x + 3 and y = -77 meet at x = -10. 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.
$8x + 3 = -77$
2
Subtract 3 from both sides:
$8x + 3 - 3 = -77 - 3 \ \Rightarrow\ 8x = -80$
3
Divide both sides by 8:
$\frac{8x}{8} = \frac{-80}{8} \ \Rightarrow\ x = -10$
4
Check: put x = -10 back into the equation.
$8\cdot(-10) + 3 = -80 + 3 = -77 \checkmark$

LaTeX source of the formulas on this page

\[ 8x + 3 = -77\ \Rightarrow\ x = -10 \]
\[ 8x + 3 = -77 \]
\[ 8x + 3 - 3 = -77 - 3 \ \Rightarrow\ 8x = -80 \]
\[ \frac{8x}{8} = \frac{-80}{8} \ \Rightarrow\ x = -10 \]
\[ 8\cdot(-10) + 3 = -80 + 3 = -77 \checkmark \]

Trying values of x in 8x + 3 = −77

x	8x + 3	Equals -77?
-12	-93	no
-11	-85	no
-10	-77	yes
-9	-69	no
-8	-61	no

Questions

What is x in 8x + 3 = −77?

The solution of 8x + 3 = −77 is x = -10.

How do you solve 8x + 3 = −77?

Subtract 3 from both sides to get 8x = -80, then divide both sides by 8 to get x = -10.

How do I check the answer?

Replace x by -10: 8(-10) + 3 = -77, which is -77.

Solve 8x + 3 = −77

How to work it out

Trying values of x in 8x + 3 = −77

Questions

Similar equations