当x=-1时.代数式ax的平方-bx+1的值为3,则（a+b-1)乘(1-a-b)的值等于?

当 x = -1 时 ,ax² - bx + 1 = 3代入得：a + b = 2(a + b - 1)(1 - a - b)= [(a + b) - 1]×[1 - (a + b)]= (2 - 1)×(1 - 2)= -1