细心算一算(1)2a5?(-a)2-(-a2)3?(-7a)(2)(4x2y+5xy-7x)-(5x2y+4xy+x)(3)(12x2y?2xy+y2)?3xy(4)(4x3y-6x2y2+12xy3)÷(2xy)(5)化简求值:已知25a2-10a+1+|4b+1|=0,求:[(4a+3b)(4a-3b)-(2a-5b)(8a+5b)]÷(-2b)的值.