Simple equations

Example 1

Find the value of p in the following equation: $p + 2 = 3$.

Solution

To make p remain alone on the left-hand side of the equation, move +2 to the other side of the equation. It becomes −2.

That is:

$p = 3 - 2$ $p = 1$

Therefore, the value of $p = 1$.

Alternatively, from $p + 2 = 3$, subtract 2 from both sides:

$p + 2 - 2 = 3 - 2$ $p = 1$

Therefore, the value of $p = 1$.

Example 2

Find the value of x in the following equation: $x + 8 = 4$.

Solution

$x + 8 = 4$.

To make x remain alone on the left-hand side of the equation, subtract 8 from both sides:

$x + 8 - 8 = 4 - 8$ $x + 0 = -4$ $x = -4$

Therefore, the value of $x = -4$.

Example 3

Find the value of k in the following equation: $-23 + k = 32$.

Solution

$-23 + k = 32$

Add 23 to both sides of the equation:

$-23 + 23 + k = 32 + 23$ $0 + k = 55$ $k = 55$

Therefore, the value of $k = 55$.