Turn two facts into two equations, solve them, and answer the question in context.
What you will learn
- Choose letters and write two equations from words
- Keep units consistent (pence or pounds)
- Interpret the solution
Two facts, two equations
"3 adult and 2 child tickets cost £41; 1 adult and 4 child tickets cost £27."
- let an adult ticket be £a and a child ticket £c
- 3a + 2c = 41
- a + 4c = 27
- second × 3: 3a + 12c = 81
- subtract: 10c = 40, so c = 4 and a = 11
Answer the question: an adult ticket costs £11 and a child ticket £4. Check with the original wording.
The rest of this lesson and its 7 practice questions are locked.
In this lesson
- Two facts, two equations
- Fixed charges and rates
- Counting and value, and lines
7 practice questions, marked as you go; about 25 minutes in all.
Key terms
How many, How much
In this unit: Simultaneous equations
Solve two equations at once by elimination, substitution and graphs, form them from problems, and (Higher) solve a linear and a quadratic equation together.
- Solving by elimination
- Solving by substitution
- Solving with graphs
- Forming simultaneous equations
- A linear and a quadratic equation