Question

(4x+5y)(4x-5y)(16x^2+25y^2)​

Answer 1

$Given \: (4x+5y)(4x-5y)(16x^2+25y^2)$

$= [(4x)^{2} - (5y)^{2} ] (16x^{2} + 25y^{2} )$

/* By algebraic identity */

$= (16x^{2} - 25y^{2}) (16x^{2} + 25y^{2} )$

$= (16x^{2})^{2} - (25y^{2})^{2}$

$= 256x^{4} - 625y^{4}$

Therefore.,

$\red{(4x+5y)(4x-5y)(16x^2+25y^2)}$

$\green {= 256x^{4} - 625y^{4}}$

•••♪

Answer 2

Answer:

(4x+5y)(4x-5y)(16x^2+25y^2)

[•using identities (a+b)(a-b)=a^2-b^2 nd (a^2+b^2)=(a+b)^2-2*a*b]

Therefore,a=4;b=5 nd in second equation a=16;b=25

Step-by-step explanation:

(4x+5y)(4x-5y)

=(4)^2-(5)^2

=16-25

=-9

(16x^2+25y^2)

=(16+25)^2-2*16*25

=(16)^2+(25)^2+2*16*25-800

=256+625+800-800

=256+625+0

=881

Now,(-9)(881)

=-7929