tentukan penyelesaian dari persamaan a. 1/2×+5=4 b.4/5 (×-1)=20 c.2/3(×+1)=1/4(3×+1)

a. 1/2x + 5 = 4
=1/2x = 4-5
1/2x = 1
x = 1/1/2
x=1/2
b. 4/5 (x-1)=20
= 4/5x - 4/5 =20
4/5x = 20 + 4/5
4/5x = 100/5 + 4/5
4/5x = 104/5
x = .....
c. 2/3 (x+1) = 1/4 (3x+1)
2/3x + 2/3 = 3/4x + 1/4
2/3x + 3/4x = 1/4 -2/3
8/4x + 9/4x = - 1/1
17/4 x = -1
x......