Question

20x square+13x-72 factoreis​

Answer 1

Correct Question : Factorise 20x² + 13x - 72

SOLUTION :

20x² + 13x - 72

As, 20 is coefficient of 20x², so multiply 20 with 72

20x² + 13x - 72

Split the middle terms

20x² - 32x + 45x - 72

4x(5x - 8) + 9(5x - 8)

(4x + 9) (5x - 8)

Zeroes are :

4x + 9 = 0

4x = -9

x = -9/4

5x - 8 = 0

5x = 8

x = 8/5

Answer 2

Answer:

(4x + 9) (5x - 8)

(4x + 9) (5x - 8) zeroes of the polynomial

(4x + 9) (5x - 8) zeroes of the polynomial ➡-9/4

(4x + 9) (5x - 8) zeroes of the polynomial ➡-9/4➡8/5

Step-by-step explanation:

given that,

the polynomial

20x² + 13x - 72

splitting the middle term

13x = 45x - 32x

also,

20x × (-72x) = 45x × (-32x)

-1440x² = -1440x²

so,

now,

20x² + 13x - 72

20x² - 32x + 45x - 72

4x(5x - 8) + 9(5x - 8)

(4x + 9) (5x - 8) = 0

4x + 9 = 0

4x = -9

x = -9/4

___________

5x - 8 = 0

5x = 8

x = 8/5

so,

✔20x² + 13x - 72

➡ (4x + 9) (5x - 8)

zeroes of the polynomial

zeroes of the polynomial ➡-9/4

zeroes of the polynomial ➡-9/4➡8/5