02Bsubstitution

= Substitution = toc

Literacy
When you are asked to __Simplify__, your answer will usually contain algebra.

Eg : __Simplify__ 3x + 5x Solution : 3x + 5x = 8x

__Evaluate__, __calculate__ and __find the value__ , all mean the same thing. In any question using these words, your answer will be a number.

Eg : __Evaluate__ 3 × 5 Solution : 3 × 5 = 15

Eg : When a = 3, __find the value__ of 4a Solution : 4 × 3 = 12

Note: __Calculate__ does __not__ mean you __have to__ use a calculator! (but you can if you need to)

Substitution
Substitution involves replacing the pronumeral with an actual value and evaluating the resulting expression.

Note : Remember that: math \\ 4a \text{ means } 4 \times a \\ \\ \dfrac{b}{3} \text{ means } b \div 3 math

** Example **
If a = 5 and b = 2, evaluate the following expressions: a) 6a + 3 b) 3ab

__**Solution:**__

a) 6a + 3 = 6 × 5 + 3 = 33

b) 3ab = 3 × 5 × 2 = 30

Fo another site that explains this idea, go here: MathsIsFun

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