Question

Expand: (√3 - 2y+ 5z )^2.

Answer 1

Answer:

Answer

Correct option is

B

9x

2

+4y

2

+25z

2

−12xy−20yz+30zx

We solve the given expression (3x−2y+5z)

2

as shown below:

(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.