Question

B) Using formula lets show that - (5x4=20)
1) (2x + 3y)2 - (2x - 3y)2 = 24xy
2) (1 + m)2 = (1 - m)2+ 41m
3) (a + 2b)2+ (a − 2b)2 = 2(a2+4b2)​

Answer 1

Answer:

using identity

{1}

i) (a+b)2=a2+b2+2ab

ii) (a-b)2= a2+b2-2àb

=(2x+3y)2-(2x-3y)2=24xy

(4x2+9y2+2×2x×3y)-(4x2-9y2+2×2x×3y)=24xy

=4x2+9y2+12xy-4x2-9y2+12xy=24xy

=24xy=24xy