If y= x^(3)+2x+5

Question

If y=x^(3)+2x+5 and z= x^(2)+7x+1 what is 2y - z in terms of x?

Answer 1

Hello Rabi,

For $2y-z$ , substitute out what y and z are each equal to,

→ $2(x^3+2x+5)-(x^2+7x+1)$

→ $2x^3+4x+10-x^2-7x-1$, by distributing 2 and the negative sign,

→ $x^2-3x+9$, by combining like terms.

Thank you for the question.

Michael Ehlers