Question

What number must be subtracted from 7 x cube minus 5 x square - 3 x minus 1 show that x minus 1 is one of its factor

Answer 1

Answer:

-2

Step-by-step explanation:

$let \: b \: be \: subtracted \\ \\ f(x) = 7 {x}^{3} - 5 {x}^{2} - 3x - 1 - b \\ \\ f(1) = 0 \\ \\ 7 - 5 - 3 - 1 - b = 0 \\ \\ - b - 2 = 0 \\ \\ b = - 2 \: \: \\ \\ hence \: - 2 \: must \: be \: subtracted \: from \: 7 {x}^{3} - 5 {x}^{2} - 3x - 1$