Solve 8x + 2 = 90

The solution of 8x + 2 = 90 is x = 11.

8x + 2 = 90\ \Rightarrow\ x = 11

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The lines y = 8x + 2 and y = 90 meet at x = 11. 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.
$8x + 2 = 90$
2
Subtract 2 from both sides:
$8x + 2 - 2 = 90 - 2 \ \Rightarrow\ 8x = 88$
3
Divide both sides by 8:
$\frac{8x}{8} = \frac{88}{8} \ \Rightarrow\ x = 11$
4
Check: put x = 11 back into the equation.
$8\cdot11 + 2 = 88 + 2 = 90 \checkmark$

LaTeX source of the formulas on this page

\[ 8x + 2 = 90\ \Rightarrow\ x = 11 \]
\[ 8x + 2 = 90 \]
\[ 8x + 2 - 2 = 90 - 2 \ \Rightarrow\ 8x = 88 \]
\[ \frac{8x}{8} = \frac{88}{8} \ \Rightarrow\ x = 11 \]
\[ 8\cdot11 + 2 = 88 + 2 = 90 \checkmark \]

Trying values of x in 8x + 2 = 90

x	8x + 2	Equals 90?
9	74	no
10	82	no
11	90	yes
12	98	no
13	106	no

Questions

What is x in 8x + 2 = 90?

The solution of 8x + 2 = 90 is x = 11.

How do you solve 8x + 2 = 90?

Subtract 2 from both sides to get 8x = 88, then divide both sides by 8 to get x = 11.

How do I check the answer?

Replace x by 11: 8(11) + 2 = 90, which is 90.

Solve 8x + 2 = 90

How to work it out

Trying values of x in 8x + 2 = 90

Questions

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