Question

Simplify :-
(a).
(4x+5y)^2-(4x-5y)^2​

Answer 1

Answer:

Just multiply it out:

(4x+5y)2 - (4x-5y)2

= 16x2 + 40xy + 25y2 - (16x2 - 40xy + 25y2)

= 80xy

You can also solve it using the difference of squares formula:

a2 - b2 = (a-b)(a+b)

Where a=4x+5y and b=4x-5y

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

(10y)(8x) = 80xy

Answer 2

Answer:

50y ( x gets cute by + -)

Step-by-step explanation:

(4x+5y)^2-(4x-5y)^2​

16x + 25y - 16x + 25y

16x - 16x +25y +25y

25y + 25y

50y