# Solving Equations

An
**
equation
**
is a mathematical statement formed by placing an equal sign between two numerical or variable expressions, as in
$3x+5=11$
.

A
**
solution
**
to an equation is a number
that can be plugged in for the
variable
to make a true number statement.

**
Example 1:
**

Solve: $15-x=12$

What number should be subtracted from $15$ to get $12$ ?

We know that 3 should be subtracted from $15$ to get $12$ . So,

$15-3=12$

Therefore,

$x=3$

Hence, the solution of $15-x=12$ is $3$ .
**
Example 2:
**

Solve: $7y=77$

What number when multiplied by $7$ gives $77$ ?

$11$ when multiplied by $7$ gives $77$ . So,

$7\cdot 11=77$

Simplify. We get:

$77=77$

So, the solution is $11$ .

**
Example 3:
**

Solve: $84\xf7z=12$

$84$ when divided by what number gives $12$ ?

The number, $84$ when divided by $7$ gives $12$ . So,

$84\xf77=12$ .

Therefore,

$z=7$ .

**
Example 4:
**

Solve: $13.4-m=9.0$

What number when subtracted from $13.4$ gives $9.0$ ?

The number, $4.4$ when subtracted from $13.4$ gives $9.0$ . So,

$13.4-4.4=9.0$ .

Therefore,

$m=4.4$ .