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Question P6 Algebra basics

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Algebra — substitute

Find 4x + 4 when x = 6.

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About this method

Algebra basics

Use a letter for an unknown number and work with what it means.

In this one. Replace every x with its given value, then multiply before adding.

3x + 5 = 233x23 - 5 = 18x18 / 3 = 6

How to spot it

A story with a repeated cost and a fixed fee, written as an expression like 4x + 4, points here. So does a value for x to substitute in.

Common mistake

Children swap the two numbers round, using the fixed fee as the price per ticket and the price per ticket as the fixed fee.

Practise a similar question

Standard Tickets cost $6 each, with a booking fee of $5. The total cost in dollars is 6x + 5. What does x represent?
All 10 with this pattern →
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