Question

If - 1 is a zero of the polynomial 2x²-x²-5x-2, find its other zeroes

Answer 1

It's 2x³ .

since -1 is the zero

:. x = -1

.: x+1 = 0

so the g(x) = x+1

For zeros = p(x)/ g(x)

= 2x³-x²-5x-2 / x+1

= 2x²-3x-2

Therefore-----

2x²-3x-2 = 2x² - 4x + x - 2

= 2x ( x - 2 ) 1 ( x - 2 )

= ( 2x + 1 ) ( x - 2 )



Therefore .......


2x + 1 = 0. or. x - 2 = 0

x = -1 / 2. or x = 2



So the other zeros are -1/2 and 2 .



HOPE IT IS MOST HELPFUL!!!!!!!!!!!!!!!!

Answer 2

Ur question is wrong sis (2x²-x²-5x-2) it should be 2x³-x²-5x-2 


As -1 being a zero, then       x = -1

                                       x + 1 = 0

So, x + 1 is a factor of 2x³ - x² - 5x - 2 
By Division Algorithm, 

Divide 2x³ - x² - 5x - 2  by x + 1  by long division

2x³ - x² - 5x - 2 ÷ x + 1    ⇒ 2x² - 3x - 2     (which u will get as quotient)

Simplifying 2x² - 3x - 2 

= 2x² - 3x - 2 

= 2x² - 4x + x - 2

= 2x(x-2) + 1(x-2)

= (2x+1)(x-2)

Then, x = -1/2 , 2

Hence other zeroes are -1/2 and 2

☺ Hope this Helps ☺