For what value of b, a polynomial in standard form , equivalent to the product of (x^2–10x+6)(2x+b):

Question

does not contain x²

Answer 1

(x²-10x+6)(2x+b) = 2x³ + bx² - 20x² - 10bx + 12x + 6b

 

our x² terms are (b-20)x²

If b = 20 there will be no x² terms

 

check with b = 20:

2x³ + 20x² - 20x² - 200x + 12x + 120

= 2x³ - 188x + 120

 

There is no x² term in the product