Why does my child swap the values of x and y?
Your child swaps the values of x and y.
Why children do it
With two equations and two unknowns, children find both numbers but lose track of which is which, especially if they found y first. Putting both values back into both equations shows straight away whether they're the right way round.
How to help at home
Ask them to write each value next to its own letter, then put both values back into each equation to check they work.
The right way
Solve the system: x + y = 10, x − y = 4
- 2x = 14Add the equations: y and −y cancel.
- x = 7Divide both sides by 2.
- 7 + y = 10Put x = 7 into the first equation.
- y = 3Subtract 7 from both sides.
- x = 7, y = 3Write both values.
Find out where your child is
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Start the free checkRelated mistakes
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