Question

已知关于x的方程2[x-(-3x+a)]=4x与(x+1)/4-6(x-a)=5/4有相同的解,求常数a的值.

Answer 1

2[x-(-3x + a)] = 4x

2(x + 3x - a) = 4x

4x - a = 2x

2x = a

x = a/2

(x + 1)/4 - 6(x - a) = 5/4

x + 1 - 24(x - a) = 5

x + 1 - 24x + 24a = 5

23x = 24a - 4

x = (24a - 4)/23

因为有相同的解

所以 a/2 = (24a - 4)/23

23a = 2(24a - 4)

23a = 48a - 8

25a = 8

a = 8/25