Question

Find the zero of polynomial 2x2+7x-4is ----
a.2 b.1/2 c.-1/2 d.-2​

Answer 1

Answer:

b. $\frac{1}{2}$

Step-by-step explanation:

To find the zero of 2x 2 +7x−4 is same as solving the equation 2x 2 +7x−4=0

$= > 2x {}^{2} + 8x - x - 4 = 0$

Collect like terms

$= > 2x {}^{2} + 7x - 4 = 0$

Rewrite the expression by writing 7x as a difference.

$= > 2 x {}^{2} + 8x - x - 4 = 0$

Factor out 2x from the expression. Factor out the negative sign from the expression.

$= > 2x \times (x + 4) - (x + 4) = 0$

Factor out x+4 from the expression.

$= > (x + 4) \times (2x - 1) = 0$

Separate into possible cases. When the product of factors 0, at least one factor is 0.

$= > x + 4 = 0 \\ \: \: \: \: \: \: \: \: \: \: \: 2x - 1 = 0$

The equation has 2 solutions.

$= > x1 = - 4 \: \: and \: \: x2 = \frac{1}{2}$