Which of the given expressions results in 0 when evaluated at x = 5? a. 5x(x − 7) b. (x + 7)(x − 2) c. (x + 5)(x − 8) d. (x − 8)(x − 5)

Option D

Step-by-step explanation:

The expressions are given in factor form.

Whenever any one factor is 0, expression is 0

Since x=5 we have x-5 =0

So wherever x-5 is a factor, the expressions has to be 0

Out of 4 expressions given we have

Option D is only having x-5 as factor

Hence option D expression

when x=5

Other expressions cannot be exactly 0 since x-5 is not a factor for any other of them

So only option D is right.

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form

1/2*qr*rs

step-by-step explanation: