Question

Expand 1. ( 3x-2y+5z ) ( 3x-2y+5z)​

Answer 1

Answer:

3x−2y+5z)

2

=(3x)

2

+(−2y)

2

+(5z)

2

+(2×3x×(−2y))+(2×(−2y)×5z)+(2×5z×3x)

(∵(a+b+c)

2

=a

2

+b

2

+c

2

+2ab+2bc+2ca)

=9x

2

+4y

2

+25z

2

−12xy−20yz+30zx

Hence, (3x−2y+5z)

2

=9x

2

+4y

2

+25z

2

−12xy−20yz+30zx.

Answer 2

Answer:

(x+y+z)² = (x²+y²+z²+2xy+2yz+2zx)

3x²-2y²+5z²+2×3x×(-2y)+2×(-2y)×5z+2×5z×3x)

9x-4y+25z-12xy-20yz+30xz