human
Recognise when it is possible to factorise an expression into a double bracket Jo says when she is factorising \( x^{2}-4 x \) she tries to think of two numbers that multiply together to give \( -4 \) and add together to give \( 0 \)

Paul says when he is factorising \( x^{2}-\frac{4}{25} \) he tries to think of two numbers that multiply together to give \( -\frac{4}{25} \) and add together to give \( \frac{2}{25} \)
Who is correct? Only Jo
gpt
When factorising into double brackets, believes the sum of the two values in the brackets equals bx rather than b