if a 2 - b 2 = 11 and a * b = 5 , find a 4 + b 4 .
"a 2 - b 2 = 11 : given a 4 + b 4 - 2 a 2 b 2 = 112 : square both sides and expand . a * b = 2 : given a 2 b 2 = 52 : square both sides . a 4 + b 4 - 2 ( 25 ) = 121 : substitute a 4 + b 4 = 171 correct answer d"
add(power(11, 2), multiply(power(5, 2), 2))