Page 102 - Knowledge Organiser Yr7 24-25

By the end of this topic you should be able to:
• Simplify an expression
• Use a formula
• Write a formula
• Work with real world formulae
• Solve an equation by adding or subtracting
• Solve an equation by multiplying or dividing
Language
Meaning
Example
Expression
Made from numbers, letters and operations but not including an equal's sign
2x + 3y
Term
Part of an expression between plus or minus signs
In the example above 2x and 3y are terms
Formula
An algebraic statement that connects things (plural formulae)
d = s xt
Distance = speed x time
Equation
An expression equal to a number or another expression
x + 3 = 11
2x – 6 = x + 3
Solve
To find the value of an unknown in equation that makes it true
If x = 5 = 12 Then x = 7
Solution
The value(s) of the unknown that the equation is true for
x = 7 is the only solution in the above equation
Substitution
To replace a letter in an algebraic expression with a number
Substituting x = 3 Into 2x + 1 Gives 2 x 3 + 1 = 7
Inverse operation
The mathematical operation that undoes an operation
Multiplying and dividing are inverse operations. When you multiply by 5 you can undo this by dividing by 5
Important things to remember:
1) E and e are not the same! Use the letters you have been given in a formula
2) You can often check if your answer is correct by substituting back into the original equation of formula
3) The inverse of addition is subtraction
4) The inverse of multiplication is division
5) The inverse of square is square root
Worked examples
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Knowledge Base: Mathematics TOPIC 11: Equations and Formulae Year 7 | Summer Term 2