The given statement can be written in the form of "if-then" as follows
If a and b are real numbers such that a2=b2 then a=b
Let p:a and b are real numbers such that a2=b2
q:a=b
The given statement has to be proved false.
For this purpose it has to be proved that if p then ∼q
To show this two real numbers a and b with a2=b2 are required such that
a≠b
Let a=1 and b=−1
a2=(1)2=1 and b2=(−1)2=1
∴a2=b2
However a≠b
Thus it can be concluded that the given statement is false