2006-09-02 18:43:58 · 11 answers · asked by double B 2 in Science & Mathematics ➔ Mathematics
a = 18-4b
3(18-4b)-4b = 14
54-12b-4b=14
54-16b= 14
40-16b=0
-16b=-40
16b=40
b=2.5
Then substituting for b:
a+4(2.5) =18
a+10=18
a=8
2006-09-02 18:50:40 · answer #1 · answered by Jim S 5 · 1⤊ 0⤋
There are a number of ways to solve this; I am using simple substitution.
Your equations are:
a + 4b = 18
3a - 4b = 14
Using the first equation, solve for a:
a = 18 - 4b Now, plug this value for a (18 - 4b) into the second equation, like this:
3(18 - 4b) - 4b = 14
54 - 12b - 4b = 14 Combine your terms, putting the variables on one side of the equation and the numbers on the other side.
54 - 14 = 12b + 4b
40 = 16b
2.5 = b Now that you know the value for b, plug that value into the first equation and solve for a.
a = 18 - 4(2.5)
a = 18 - 10 = 8
a = 8
2006-09-03 02:03:32 · answer #2 · answered by nammy_410 2 · 0⤊ 0⤋
add the qiven 2 equations
4a = 32
so a = 8
put in 1 8+ 4b= 18
so 4b = 10
b = 2.5
so a =8 b = 2.5
2006-09-03 01:56:24 · answer #3 · answered by Mein Hoon Na 7 · 0⤊ 0⤋
a +4b=18
3a -4b=14
as there is -ve & +ve 4b we add them
a+ 4b + 3a - 4b = 18 + 14
4b & -4b gets cancelled
a+3a =18+14
4a =32
a=32/4
=8
a + 4b= 18
8 +4b = 18
4b= 18-8
4b=10
b=10/4= 2.5
2006-09-03 01:59:56 · answer #4 · answered by sweetgrace 2 · 0⤊ 0⤋
a +4b = 18
3a - 4b = 14
elimination:
4a = 32
a = 8
substitute:
a=8
a+4b=18
8+4b=18
4b=10
b=5/2
a=8, b=5/2
2006-09-03 02:03:27 · answer #5 · answered by Lin 2 · 0⤊ 0⤋
a+4b=18
a=18-4b
now put the value of a in the second equation,
3(18-4b)-4b=14
54-12b-4b=14
-16b=14-54
-16b=-40
b=40/16
b=2.5
now put the value of b in equation one
a+4x2.5=18
a+10=18
a=18-10
a=8
2006-09-03 06:56:18 · answer #6 · answered by sam 2 · 0⤊ 0⤋
a+4b=18
-4b -4b
a=18-4b
3(18-4b) -4b=14
54-12b-4b=14
-54 -54
-12b-4b=-40
-16b=-40
16b=40
___ __
16 16
b=40/16-> 5/2
2006-09-03 01:55:22 · answer #7 · answered by SweetBrunette 5 · 0⤊ 0⤋
a+4b=14-------1
3a-4b=18-------2
adding 1&2, we get, 4a=32,so a=8
again,in 1,substituting a we get,8+4b=14so b=2.5
2006-09-03 02:00:28 · answer #8 · answered by cutecurious 1 · 0⤊ 0⤋
a + 4b = 18
3a - 4b = 14
---------------------------
4a = 32
a = 32/ 4
a =8
2006-09-06 23:02:45 · answer #9 · answered by answerer 2 · 0⤊ 0⤋
10+4(2)=18
and
3(10)-4(4)=14
2006-09-03 01:51:56 · answer #10 · answered by <('_')> 4 · 0⤊ 1⤋