# Solving equations with brackets

### Example

Solve the equation .

The equation contains a set of brackets. The easiest way to solve equations with brackets is to expand the brackets.

Expand the bracket:

Isolate by adding 15 to each side:

Isolate by dividing by 10:

or 3.4

Question

The area of this rectangle is 56 cm2. Find the value of .

. This means will all be multiplied by 7. To show this in algebra, use a bracket for to show that both terms are being multiplied by 7.

7 multiplied by can be written as as multiplication signs are not used in algebra.

Area = 56 cm2, base = (3r + 2) cm, height = 7 cm

So setting up an equation using this information gives:

Multiply out the bracket.

Isolate by subtracting 14 from both sides:

Isolate by dividing both sides by 21:

Check that this answer is correct by substituting into the original equation.

The equation balances, so is the correct answer.