The expression (11.98 $\times$ 11.98 + 11.98 $\times$ x + 0.02 $\times$ 0.02) will be a perfect square for $x$ equal to:
0.02
0.2
0.04
0.4
Explanation:
Given expression = (11.98)2 + (0.02)2 + 11.98 x $x$.
For the given expression to be a perfect square, we must have
11.98 x $x$ = 2 x 11.98 x 0.02 or $x$ = 0.04