If a and b are rational numbers, find 'a' and 'b' when
√7−2√7+2=a√7+b
a=−43, b=113
√7−2√7+2=a√7+b
√7−2√7+2×√7−2√7−2=a√7+b
(√7−2)2(√7)2−(2)2=a√7+b
The numerator is of the form (a−b)2 and the denominator is of the form a2−b2
∴(√7)2−2(√7)(2)+(2)27−4=a√7+b
7−4√7+43=a√7+b
−43√7+113=a√7+b
Comparing we get,a=−43, b=113