Question

Find the coefficient of y in the expansion of 2 y - 3 whole square

Answer 1

(2y-3)^2
=4y square+ 9-6y
coefficient of y is
4y-6

Answer 2

$\sf{\underline {\large{BINOMIAL\:THEOREM}}}$ :

$\tt{(2y \:-\: 3)}^{2}$ = $\tt{2C_0 (2y)^{2} + 2C_1(2y)(-3) +2C_2 *9}$

Coefficient of y = $2C_1 (-3)$

➡️ - 6