Question

Find the coefficient of x² in the product (x-1)(1-2x)

Answer 1

Answer:

$(x - 1)(1 - 2x) \\ = x(1 - 2x) - 1(1 - 2x) \\ = x - 2 {x}^{2} - 1 + 2x \\ = - 2 {x}^{2} + 3x - 1 \\ coefficient \: of \: {x}^{2} = - 2$