Question

Expand (2x+y-3z)².
.
.
pls explain step wise​

Answer 1

Answer:

We know that (a+b+c)² = a²+b²+c² +2(ab+bc+ca)

Here a=2x , b =y and c =-3z

So 4x²+y²+9z²+2(2xy -3zy -6xz)

= 4x² +y² +9 z² +4xy -6yz -12xz

Answer 2

Answer:

$4x^{2}  + y ^{2}  + 9z^{2}  - 4xy - 6yz + 12xz$

Step-by-step explanation:

$→ (2x+y-3z)²$

$→ (2x)^{2}+ (-y) ^{2}+ (3z) ^{2}+ 2(2x)(-y) + 2(-y)(3z) + 2(3z)(2x)$

$\green{ \boxed{→4x^{2}  + y ^{2}  + 9z^{2}  - 4xy - 6yz + 12xz}}$

Identity used -

$(a + b + c) ^{2}  = a ^{2}  + b ^{2} + c ^{2}  + 2ab + 2bc + 2ca$