Question

expand using suitable Identity (4a-2b-5c)*2​

Answer 1

Answer:

Given

${(4a - 2b - 5c)}^{2}$

Find

Expand the following

Solution

Using the following formula ⤵

${ \boxed{ \to{ \sf{( {x + y + z)}^{2} = {x}^{2} + {y}^{2} + {z}^{2} + 2xy + 2yz + 2zx }}}}$

Take x = 4a , y = -2b , z = -5c

${ \implies{ \sf{ {(4a)}^{2} + {( - 2b)}^{2} + {( - 5c)}^{2} + 2(4a)( - 2b) + 2( - 2b)( - 5c) + 2( - 5c)(4a) }}}$

${ \implies{ \sf{16 {a}^{2} + 4 {b}^{2} + 25 {c}^{2} - 16ab + 20bc - 40ca }}}$