(1)〔x+a〕〔x+b〕=x2+mx+36
即x^2+(a+b)x+ab=x^2+mx+36
得a+b=m,且ab=36.因为ab为整数,故可以取(1,36),(2,18),(3,12),(4,9),(6,6),所以m可以为37,20,15,13,12.
(2)n(n+5)-(n+2)(n-3)=6(n+1),因为n为正整数,故总能被6整除,且值为n+1,由n确定.
(3)(ax+b)(x+2)=x^2-4
即ax^2+(2a+b)x+2b=x^2-4
得a=1,b=-2.
所以ab=-2