Solve 7x − 7 = 105

The solution of 7x − 7 = 105 is x = 16.

7x - 7 = 105\ \Rightarrow\ x = 16

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The lines y = 7x − 7 and y = 105 meet at x = 16. 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 subtraction, then the multiplication.
$7x - 7 = 105$
2
Add 7 to both sides:
$7x - 7 + 7 = 105 + 7 \ \Rightarrow\ 7x = 112$
3
Divide both sides by 7:
$\frac{7x}{7} = \frac{112}{7} \ \Rightarrow\ x = 16$
4
Check: put x = 16 back into the equation.
$7\cdot16 - 7 = 112 - 7 = 105 \checkmark$

LaTeX source of the formulas on this page

\[ 7x - 7 = 105\ \Rightarrow\ x = 16 \]
\[ 7x - 7 = 105 \]
\[ 7x - 7 + 7 = 105 + 7 \ \Rightarrow\ 7x = 112 \]
\[ \frac{7x}{7} = \frac{112}{7} \ \Rightarrow\ x = 16 \]
\[ 7\cdot16 - 7 = 112 - 7 = 105 \checkmark \]

Trying values of x in 7x − 7 = 105

x	7x − 7	Equals 105?
14	91	no
15	98	no
16	105	yes
17	112	no
18	119	no

Questions

What is x in 7x − 7 = 105?

The solution of 7x − 7 = 105 is x = 16.

How do you solve 7x − 7 = 105?

Add 7 to both sides to get 7x = 112, then divide both sides by 7 to get x = 16.

How do I check the answer?

Replace x by 16: 7(16) − 7 = 105, which is 105.

Solve 7x − 7 = 105

How to work it out

Trying values of x in 7x − 7 = 105

Questions

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