Solve 4x + 7 = −9

The solution of 4x + 7 = −9 is x = -4.

4x + 7 = -9\ \Rightarrow\ x = -4

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The lines y = 4x + 7 and y = -9 meet at x = -4. 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.
$4x + 7 = -9$
2
Subtract 7 from both sides:
$4x + 7 - 7 = -9 - 7 \ \Rightarrow\ 4x = -16$
3
Divide both sides by 4:
$\frac{4x}{4} = \frac{-16}{4} \ \Rightarrow\ x = -4$
4
Check: put x = -4 back into the equation.
$4\cdot(-4) + 7 = -16 + 7 = -9 \checkmark$

LaTeX source of the formulas on this page

\[ 4x + 7 = -9\ \Rightarrow\ x = -4 \]
\[ 4x + 7 = -9 \]
\[ 4x + 7 - 7 = -9 - 7 \ \Rightarrow\ 4x = -16 \]
\[ \frac{4x}{4} = \frac{-16}{4} \ \Rightarrow\ x = -4 \]
\[ 4\cdot(-4) + 7 = -16 + 7 = -9 \checkmark \]

Trying values of x in 4x + 7 = −9

x	4x + 7	Equals -9?
-6	-17	no
-5	-13	no
-4	-9	yes
-3	-5	no
-2	-1	no

Questions

What is x in 4x + 7 = −9?

The solution of 4x + 7 = −9 is x = -4.

How do you solve 4x + 7 = −9?

Subtract 7 from both sides to get 4x = -16, then divide both sides by 4 to get x = -4.

How do I check the answer?

Replace x by -4: 4(-4) + 7 = -9, which is -9.

Solve 4x + 7 = −9

How to work it out

Trying values of x in 4x + 7 = −9

Questions

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