Question

已知 a,b互为相反数 c,d互为倒数 x等于3（a减1）减（a减2b)y等于c的平方d加d的平方减（c分之d加c减2）

Answer 1

x = 3(a - 1) - (a - 2b) = 3(a - 1) - (a + 2a) = -3

y = c²d + d² - (d/c + c - 2) = 1/d + d² - (d² + 1/d - 2) = 1/d + d² - d² - 1/d + 2 = 2

(2x - y)/3 - (3x + 2y)/6 = (4x - 2y - 3x - 2y)/6 = (x - 4y)/6 = (-3 - 4)/6 = -7/6