Question

If 1 and (-2) are two zeros of the polynomial (x cube (-4x) square - 7 x + 10), then find its third zero

Answer 1

heya...!!!!


given that:-

its two zeroes are 1, (-2)

then,

(x - 1)(x + 2)

=> x² + 2x - x - 2

=> x ² + x - 2



x² + x - 2)x³ - 4x² - 7x + 10(x - 5
x³ + x² - 2x
(-) __(-) __(+)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
- 5x² - 5x + 10
-5x² - 5x + 10
(+) ___(+) __(-)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
0 0 0

Now the third zeros jst

X - 5

=> x = 5