Answer the following Math Algebra question(F.1)

1.
(1 + x) * 4 = 4 + 4x

2.
9k - 1 = - 6k - 31
9k = - 6k - 30
15k = -30
k = -2

3.
10 - 5x = 1 - x + 1 + 2x
10 - 5x = 2 + x
-6x = - 8
x = 4 / 3

4.
0.4a - 0.2(a - 6) = 0.5
0.4a - 0.2a + 1.2 = 0.5
0.2a = - 0.7
2a = -7
a = - 7 / 2

5.
5[2(y-4.2)+y-1]=y-5
5[2y - 8.4 + y - 1] = y - 5


2006-10-30 16:40:48 補充：
5.5[2y - 8.4 y - 1] = y - 510y - 42 5y - 5 = y - 515y - 47 = y - 514y = 42y = 3

Q1.
(1+x)×4=4+4x

Q2.
9k-1=-6k-31.
9k+6k = -31+1
15k = -30
k = -2

Q3.
10-5x=1-x+1+2x
10-1-1 = 5x -x +2x
8 = 6x
x = 4/3


Q4.
0.4a-0.2(a-6)=0.5
0.4a - 0.2a - 0.2(-6) = 0.5
0.2a+1.2 = 0.5
0.2a = -0.7
a = -3.5

Q5.
5[2(y-4.2)+y-1]=y-5
10y-42+y-1 = y-5
10y-43 = -5
10y = 38
y = 3.8

2006-10-30 16:32:05 補充：
Q5.5[2(y-4.2) y-1]=y-510y-42 *5y-5* = y-515y-47 = y-514y = 42y = 3

2006-10-30 16:36:44 補充：
Q5.10y-42*加5y-5 = y-5唔知點解個*加*號出唔到~~