Question

write co- efficient of y in the expansion of( 5- y)².

Answer 1

Hello friend

Here's your answer

(5-y)²

Using the identity (a-b)²=a²-2ab+b²

(5-y)²=(5)²-2(5)(y)+y²

=25-10y+y²

The co efficient of y² is 10

Hope it helps!!

Answer 2

your answer is here:-)
(5-y)^2 = 25+y^2-10y with (a-b)=(a^2+b^2-2ab)
So co-fficient of y will be -10
hope you like it!!!!!