Show worked solution
Worked solution
Look for an equals sign
Scan the statement: there is no = sign anywhere.
Recall the definition
An expression is just a collection of terms with no equals sign.
State the answer
So 3x + 5 is an expression.
Free GCSE Algebraic vocabulary practice questions with full step-by-step worked solutions. Covers expression, equals sign, equation, terms. Practise exam-style problems and check your method.
Look for an equals sign
Scan the statement: there is no = sign anywhere.
Recall the definition
An expression is just a collection of terms with no equals sign.
State the answer
So 3x + 5 is an expression.
Look for an equals sign
There is an = sign.
Recall the definition
An equation has an equals sign and is true only for particular value(s) of the letter.
State the answer
So is an equation.
Recall equation versus identity
An equation has an equals sign and is true only for particular value(s) of the letter. An identity is true for every value of the letter and is written with the identity sign.
Ask whether it is true for all x
Check whether every value of x works.
Test some values
True for but not for .
Find the solutions
Only these two values make it true.
Decide equation or identity
Since it is not true for all x, it is not an identity.
State the answer
So is an equation.
Identify the terms
Split at each + sign.
Count the terms
There are 3 terms.
Find the x squared term
A lone means 1 times .
Coefficient of x squared
The coefficient of is 1.
Coefficient of x
The number multiplying x is 9.
Find the constant term
The term with no letter is 20.
Expand the brackets
Multiply every term in the first bracket by each in the second.
Collect like terms
5x + 4x combine to 9x.
Compare both sides
The two sides match for all x, so it is an identity.
State all the answers
3 terms; coefficients 1 and 9; constant 20; the factorisation is an identity.
Look at the whole statement
It has an equals sign and two letters.
Check for a formula
It gives a rule for cost from miles, so it is a formula.
Classify the whole statement
So is a formula.
Identify the subject
The subject is the letter on its own: C.
List the letters
The letters used are C and m.
State the variables
The variables are C and m.
Find the constant term
The fixed fee is the constant term 3.
Interpret the constant
The 3 is a fixed charge that does not depend on distance.
Find the term in m
The term containing m is 2m.
Read off the coefficient of m
The coefficient of m is 2.
Interpret the coefficient
The 2 is the cost per mile travelled.
Look at 3 + 2m alone
On its own there is no equals sign.
Classify 3 + 2m alone
So 3 + 2m by itself is an expression.
Bring the parts together
Collect all answers.
State all the answers
It is a formula; subject C; variables C and m; constant 3; coefficient of m is 2 (cost per mile); and 3 + 2m alone is an expression.
Create a free account to work through every GCSE Algebraic vocabulary question with instant step-by-step worked solutions, progress tracking and interactive lessons.
No card required · Free forever