Question

Find the co-efficient of y in the expansion of (5 -2y)2​

Answer 1

Answer:

10

The given expression is

(5-y)^2(5−y)

2

We need to find the coefficient of y in the expansion of given expression.

Algebraic formula:

(a-b)^2=a^2-2ab+b^2(a−b)

2

=a

2

−2ab+b

2

Using algebraic formula we get

(5-y)^2=(5)^2-2(5)(y)+(y)^2(5−y)

2

=(5)

2

−2(5)(y)+(y)

2

(5-y)^2=25-10y+y^2(5−y)

2

=25−10y+y

2

Here, the coefficient of y is -10.

Therefore, the coefficient of y in the expansion of given expression is -10.