Maths puzzles:
1. Prove
-*-=+
-1*0=0
-1*(-1+1)=0
(-1*(-1))+(-1*1)=0, since
a*(b+c)=a*b+a*c
(-1*(-1))+(-1)=0
(-1*(-1))-1=0
(-1*(-1))=1, hence -*-=+
2.
Magic Square( other similar things explained at
1 2 3 รจ
4 5 6
7 8 9
Draw lines diagonally, then jump each digit to empty
boxes. It will become a magic square. Add any row, column or diagonal it will
give same result.
Similarly, 4X4 magic square.
3.
Prove
2=1
Assume, x=1,
Multiply with x on both sides
X2=x
Deduct one on both sides
X2-1=x-1
(x-1)(x+1)=(x-1),
Divide by x-1 on both sides.
x+1=1,
substitute x=1,
2=1
Something is wrong in above proof,
find out what?
4. How many squares are there in below diagram? [a 3X3 square]
