Question

If (3x-4)5x+7=15x²-ax-28 then a is equal​

Answer 1

Step-by-step explanation:

(3x-4)5x+7=15x²-ax-28

⇒5x(3x-4)+7(3x-4) = 15x²-ax-28

⇒15x²-20x+21x-28 = 15x²-ax-28

⇒15x²+x-28 = 15x²-ax-28

Comparing LHS & RHS,

a = -1

Answer 2

Answer:

15 = a

Step-by-step explanation:

[3x-4]5x + 7 = 15x^2 -ax - 28

15x^2 - 20x + 7 = 15x^2 -ax - 28

15x^2 is cutted and we get

- 20x +7 = -ax - 28

-35 = -ax - 20x

-35 = -x [ a+20]

we take x =1

-35 = -a - 20

-15 = -a

15 = a