i need help solving these equations
1. 7(2 - 4y) + 14y =42
2. 5b - 3/4 b + 6 = 1/4
3. 3x + 6 = 12x + 24
4. 0.4c = 0.7c - 2.7
thanx for ur help =)))
2007-04-13 04:07:26 · 12 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
thanx guy u really helped me out!!!
2007-04-13 04:31:12 · update #1
7(2 - 4y) + 14y = 42
14 - 28y + 14y = 42
14 - 14y = 42
14 - 14y - 14 = 42 - 14
- 14y = 28
- 14y / - 14 = 28 / - 14
y = - 2
- - - - - - - -
5b - 3/4b + 6 = 1/4
4(5b) - 4(3/4b) + 4(6) = 4(1/4
20b - 3b + 24 = 1
17b + 24 = 1
17b + 24 - 24 = 1 - 24
17b = - 23
17b / 17 = - 23 / 17
b = - 23/17
b = 1 6/7
- - - - - - -
3x + 6 = 12x + 24
3x + 6 - 3x = 12x + 24 - 3x
6 = 9x + 24
6 - 24 = 9x + 24 - 24
- 18 = 9x
- 18 / 9 = 9x / 9
- 18 / 9 = x
- 2 = x
- - - - - - - -
0.4c = 0.7c - 2.7
0.4c - 0.4c = 0.7c - 2.7 - 0.4c
0 = 0.3c - 2.7
0 + 2.7 = 0.3c - 2.7 + 2.7
2.7 = 0.3c
2.7 / 0.3 = 0.3c . 0.3
2.7 / 0.3 = c
9 = c
- - - - - - - s-
2007-04-13 04:36:31 · answer #1 · answered by SAMUEL D 7 · 0⤊ 0⤋
1. 7(2 - 4y) + 14y =42
first multiply 7 by what inside the bracket you get
14- 28 y + 14y = 42
14 -14y =42 rearrange it
-14y =42 -14
-14y =28 -----> y = -2
2. 5b - 3/4 b + 6 = 1/4
4.25b + 6 =1/4 rearrange it
4.25 b = 1/4 -6 ---> 4.25 b= -5.75
b= -5.75/4.25= -23/17 or -1.352941176
3. 3x + 6 = 12x + 24 rearrange it
3x-12x =24 - 6
-9x =18 ---> x=-18/9=-2
4. 0.4c = 0.7c - 2.7 just rearrange it
0.4c -0.7c = -2.7
-0.3c = -2.7 negative sign cancel out each other
c = 9
2007-04-13 04:21:51 · answer #2 · answered by Khalidxp 3 · 0⤊ 0⤋
7(2 - 4y) + 14y = 42
2 - 4y + 2y = 6
-2y = 4
y = -2
5b - (3/4)b + 6 = 1/4
20b - 3b + 24 = 1
17b = -23
b = -23/17
3x + 6 = 12x + 24
-18 = 9x
-2 = x
0.4c = 0.7c - 2.7
2.7 = 0.3c
9 = c
2007-04-13 04:14:35 · answer #3 · answered by Philo 7 · 0⤊ 0⤋
It would take you less time to do these than to type them.
If this is your idea of difficult, I think I see 'fries' in your future... hopefully not behind the register, though.
7(2 - 4y) + 14y =42
14 - 28y + 14y = 42
1 - y = 3
y = -2
5b - 3/4 b + 6 = 1/4
20b -3b + 24 = 1
17b = -23
b = -23/17
3x + 6 = 12x + 24
-18 = 9x
x = -2
0.4c = 0.7c - 2.7
4c = 7c -27
27 = 3c
c = 9
2007-04-13 04:13:11 · answer #4 · answered by MamaMia © 7 · 0⤊ 0⤋
All you need to do is perform operations and combine like terms. 1.) 7(2) - 7(4y) +14y = 42
14 - 28y +14y = 42
- 14y = 28
y = 28/-14 y= -2
2007-04-13 04:19:01 · answer #5 · answered by dwinbaycity 5 · 0⤊ 0⤋
7(2 - 4y) + 14y =42
14-28y +14y = 42
-14y = 28
y = -2
-----------
5b - 3/4 b + 6 = 1/4
17b/4 = -23/4
b = -23/17
---------------
3x + 6 = 12x + 24
9x= -18
x= - 2
----------
c=9
2007-04-13 04:14:55 · answer #6 · answered by Maga M 1 · 0⤊ 0⤋
You mean you want someone to do them for you? These problems are simple. Combine like terms- Thats all there is to it. It is simple arithmetic. If the variables are on opposite sides of the equation, get them together. We could help you better if we knew what exactly what you don't understand about these problems.
2007-04-13 04:12:37 · answer #7 · answered by Maid of Constant Sorrow 4 · 0⤊ 0⤋
these are simple pre-algebra problems. you should try doing it yourself. if you have any problem with it, talk to your teacher or parent for additional help. having someone else do this for you, will not help you at all, you won't learn.
2007-04-13 04:11:30 · answer #8 · answered by (♥_♥) 6 · 0⤊ 0⤋
how about you post your solution and we tell you if its right? isnt that the way to learn. this is the simplest problems so try it first
2007-04-13 04:12:05 · answer #9 · answered by Anonymous · 0⤊ 0⤋
isolate the variable
2007-04-13 05:19:04 · answer #10 · answered by TBU 2 · 0⤊ 0⤋