Solve the following equations
1. (m+3)/2=-4m
2. s/3=-0.2(1-3s)
2006-11-16 13:51:16 · 7 個解答 · 發問者 ? 7 in 科學 ➔ 數學
1. (m+3)/2 = -4m
m+3 = -8m
3=-9m
m = -(1/3)
2. s/3 = -0.2(1-3s)
s/3 = -0.2+0.6s
s = -0.6+1.8s
0.8s = 0.6
s = 3/4
做這類數最要緊是懂得換主項。將主項換在一邊就自然計到答案的。當然要用到乘法分配性質了。
2006-11-16 15:39:29 · answer #1 · answered by ? 5 · 0⤊ 0⤋
Q1.
(m+3)/2 = 4m
(m+3) = 4m*2
(m+3) = 8m
3 = 8m-m
3 = 7m
Hence,
m = 3/7
Q2.
s/3 = -0.2(1-3s)
s = -0.2*3*(1-3s)
s = -0.6*(1-3s)
s = -0.6+1.8s
0.6 = 1.8s - s
0.6 = 0.8s
Hence,
s = 0.6/0.8 = 0.75
2006-11-16 20:21:20 補充：
Correction:Q1(m+3)/2 = -4m(m+3) = -4m*2(m+3) = -8m3 = -8m-m3 = -9mHence,m = -1/3 (Correct Answer!!!)
2006-11-16 15:19:14 · answer #2 · answered by ? 4 · 0⤊ 0⤋
1. (m+3)/2 = -4m
m+3 = -8m
3=-9m
m = -(1/3)
2. s/3 = -0.2(1-3s)
s/3 = -0.2+0.6s
s = -0.6+1.8s
0.8s = 0.6
s = 3/4
2006-11-16 14:04:40 · answer #3 · answered by iok yiu 2 · 0⤊ 0⤋
1. (m+3)/2=-4m
1/2m+3/2=-4m
3/2=-4m-1/2m
m=3/2(-2/9)
m=-1/3
2.s/3=-0.2(1-3s)
1/3s=-0.2+3s
0.2=3s-1/3s
8/3s=0.2
s=3/40
2006-11-16 14:01:23 · answer #4 · answered by ? 2 · 0⤊ 0⤋
1. (m+3)/2=-4m
-8m=m+3
9m= -3
m= -1/3
2. s/3=-0.2(1-3s)
s=3( -0.2)(1 -3s)
s= -0.6+1.8s
0.8s= 0.6
s=0.75
2006-11-16 14:00:01 · answer #5 · answered by Amby 6 · 0⤊ 0⤋
1.m+3/2=-4m
m+3 =(-4m)2
9m =-3
m=-1/3
2.s/3=-0.2(1-3s)
s/3 = 0.2-0.6s
s=0.6-1.8s
2.8s=0.6
s=3/14
2006-11-16 13:59:26 · answer #6 · answered by ? 1 · 0⤊ 0⤋
(1)
(m+3)/2=-4m
m+3=-8m
-9m=3
m=-1/3
(2)
s/3=-0.2(1-3s)
s/3=-0.2-0.6s
10s=-6-18s
28s=-6
s=-3/14
2006-11-16 13:58:54 · answer #7 · answered by 打倒美帝紙老虎 6 · 0⤊ 0⤋