Question

What must be subtracted from $4x^3-3x+5$ to get $2x^2-3x^3+5x-2$ ?

• A. - - 8x + 7
  
• B. + - 8x + 7
  
• C. - - 8x + 3
  
• D. - - 8x + 7
  

Answer 1

The correct option is D

- - 8x + 7

Let P be the algebraic expression that is to be subtracted from $4x^3-3x+5$

Then, ($4x^3-3x+5$) $-$ P = $2x^2-3x^3+5x-2$

$⟹$ P = ($4x^3-3x+5$) $-$ ($2x^2-3x^3+5x-2$)

= $4x^3-3x+5-2x^2+3x^3-5x+2$

= $4x^3+3x^3-2x^2-3x-5x+5+2$

= $7x^3-2x^2-8x+7$