Substitution worksheet

10 GCSE practice questions with answers, free to print. Every sheet is generated, so you can make a fresh one whenever you need it.

10 questions 30 marks Sheet 1

3 marks
\(y = 7x + 6\)

(a)
Work out the value of \(y\) when \(x = 12\).

(b)
Work out the value of \(y\) when \(x = -9\).
2 marks
Work out the value of \(2p - 5q\) when \(p = 5\) and \(q = -4\).
4 marks
A taxi firm works out the cost of a journey using the formula

\(C = 3m + 4\)

where \(C\) is the cost in pounds and \(m\) is the number of miles travelled.

(a)
Amara travels 4 miles. Work out the cost of her journey.

(b)
Calculate how much more a journey of 11 miles costs than a journey of 4 miles.
3 marks
Find the value of \(3x^2 + 4x - 3\) when \(x = -1\).
3 marks
\(y = \frac{ 6x + 2 }{ 5 }\)

Work out the value of \(y\) when \(x = -2\).
3 marks
A formula connecting four quantities is

\(v = u + at\)

\(v = 14\), \(u = 2\) and \(t = 6\).

Work out the value of \(a\).
3 marks
\(y = 5x + 9\)

(a)
Find the value of \(y\) when \(x = 9\).

(b)
Find the value of \(y\) when \(x = -9\).
2 marks
Calculate the value of \(7p + 3q\) when \(p = 5\) and \(q = -3\).
4 marks
A taxi firm works out the cost of a journey using the formula

\(C = 5m + 4\)

where \(C\) is the cost in pounds and \(m\) is the number of miles travelled.

(a)
Marcus travels 5 miles. Work out the cost of his journey.

(b)
Work out how much more a journey of 16 miles costs than a journey of 5 miles.
3 marks
Work out the value of \(3x^2 -x - 12\) when \(x = -6\).

Answers