Question

已知（-5x+9）除以x^-9等于a/(x+3)+b/(x-3),则a^+b^等于多少?

Answer 1

∵ [a/(x+3)+b/(x-3)](x²-9)=ax-3a+bx+3b=(a+b)x+3(b-a)

∴ a+b=-5 3b-3a=9 => b-a=3 =>2b=-2 => b=-1 => a=-4

∴ a²+b²=(-4)²+(-1)²=16+1=17