Solve 10x + 9 = −51

The solution of 10x + 9 = −51 is x = -6.

10x + 9 = -51\ \Rightarrow\ x = -6

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The lines y = 10x + 9 and y = -51 meet at x = -6. 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.
$10x + 9 = -51$
2
Subtract 9 from both sides:
$10x + 9 - 9 = -51 - 9 \ \Rightarrow\ 10x = -60$
3
Divide both sides by 10:
$\frac{10x}{10} = \frac{-60}{10} \ \Rightarrow\ x = -6$
4
Check: put x = -6 back into the equation.
$10\cdot(-6) + 9 = -60 + 9 = -51 \checkmark$

LaTeX source of the formulas on this page

\[ 10x + 9 = -51\ \Rightarrow\ x = -6 \]
\[ 10x + 9 = -51 \]
\[ 10x + 9 - 9 = -51 - 9 \ \Rightarrow\ 10x = -60 \]
\[ \frac{10x}{10} = \frac{-60}{10} \ \Rightarrow\ x = -6 \]
\[ 10\cdot(-6) + 9 = -60 + 9 = -51 \checkmark \]

Trying values of x in 10x + 9 = −51

x	10x + 9	Equals -51?
-8	-71	no
-7	-61	no
-6	-51	yes
-5	-41	no
-4	-31	no

Questions

What is x in 10x + 9 = −51?

The solution of 10x + 9 = −51 is x = -6.

How do you solve 10x + 9 = −51?

Subtract 9 from both sides to get 10x = -60, then divide both sides by 10 to get x = -6.

How do I check the answer?

Replace x by -6: 10(-6) + 9 = -51, which is -51.

Solve 10x + 9 = −51

How to work it out

Trying values of x in 10x + 9 = −51

Questions

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