Solve 7x + 7 = −28

The solution of 7x + 7 = −28 is x = -5.

7x + 7 = -28\ \Rightarrow\ x = -5

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The lines y = 7x + 7 and y = -28 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.
$7x + 7 = -28$
2
Subtract 7 from both sides:
$7x + 7 - 7 = -28 - 7 \ \Rightarrow\ 7x = -35$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{-35}{7} \ \Rightarrow\ x = -5$
4
Check: put x = -5 back into the equation.
$7\cdot(-5) + 7 = -35 + 7 = -28 \checkmark$

LaTeX source of the formulas on this page

\[ 7x + 7 = -28\ \Rightarrow\ x = -5 \]
\[ 7x + 7 = -28 \]
\[ 7x + 7 - 7 = -28 - 7 \ \Rightarrow\ 7x = -35 \]
\[ \frac{7x}{7} = \frac{-35}{7} \ \Rightarrow\ x = -5 \]
\[ 7\cdot(-5) + 7 = -35 + 7 = -28 \checkmark \]

Trying values of x in 7x + 7 = −28

x	7x + 7	Equals -28?
-7	-42	no
-6	-35	no
-5	-28	yes
-4	-21	no
-3	-14	no

Questions

What is x in 7x + 7 = −28?

The solution of 7x + 7 = −28 is x = -5.

How do you solve 7x + 7 = −28?

Subtract 7 from both sides to get 7x = -35, then divide both sides by 7 to get x = -5.

How do I check the answer?

Replace x by -5: 7(-5) + 7 = -28, which is -28.

Solve 7x + 7 = −28

How to work it out

Trying values of x in 7x + 7 = −28

Questions

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