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Algebraic expressions - OCRSimplifying expressions

Letters can be used to stand for unknown values or values that can change. Formulas can be written and equations solved to solve a range of problems in science and engineering.

Part of MathsAlgebra

Simplifying expressions

Collecting like terms

Collecting like terms means to simplify terms in expressions in which the variables are the same. In the expression \(5a + 2b + 3a - 6b\), the terms \(5a\) and \(+ 3a\) are like terms, as are \(2b\) and \(-6b\).

Example 1

Simplify \(b + b + b + b\).

Adding the four like terms together gives \(4b\).

Example 2

Simplify \(5m + 3m - 2m\).

In this expression, all the terms are like terms as the variable in each term is \(m\). Simplify the expression in order:

\(5m + 3m = 8m\)

\(8m - 2m = 6m\)

Question

Simplify \(9c {-7d} + c + 3d + 5\).

Question

Simplify \(2p^2 + 3p + p^2\).

Multiplying and dividing expressions

Algebraic expressions can also be multiplied and divided.

Example 1

Simplify \(a \times a\).

Multiplying a number or letter by itself is called squaring. This means \(a \times a = a^2\) (read as 'a squared'). In \(a^2\), the 2 is known as the or power. Powers tell us how many times a number or letter has been multiplied by itself.

Example 2

Simplify \(b \times b \times b\).

In this example, \(b\) is being multiplied by itself three times. The power of \(b\) will be three, so \(b \times b \times b = b^3\).

Question

Simplify \(3d \times 5d\).

Question

Simplify \(16e^2 \div 2e\).