Question

find the product of : (-2x+5y-3z)²​

Answer 1

Step-by-step explanation:

(−2x+5y−3z)

2

is of the form (a+b+c)

2

(a+b+c)

2

=a

2

+b

2

+c

2

+2ab+2bc+2ca

where a=−2x,b=5y,c=−3z

∴(−2x+5y−3z)

2

=(−2x)

2

+(5y)

2

+(−3z)

2

+2(−2x)(5y)+2(5y)(−3z)+2(−3z)(−2x)

=4x

2

+25y

2

+9z

2

−20xy−30yz+12zx.

Answer 2

(−2x+5y−3z) ^2 is of the form

(a+b+c) ^2

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

where a=−2x,b=5y,c=−3z

∴(−2x+5y−3z)^2

=(−2x) 2+(5y) 2+(−3z) 2 +2(−2x)(5y)+2(5y)(−3z)+2(−3z)(−2x)

=4x^2 +25y^2 +9z^2−20xy−30yz+12zx.