5x-7=43
8x+4=-60
-30=3+3x
7z-1=23-5z
3a-8=-8-5a
2x+3=x-4
4x+5=12x-15x-2
9(5x-2)=27
Please HELP!!!
2007-01-27 09:18:38 · 9 answers · asked by katiekcat5 3 in Science & Mathematics ➔ Mathematics
I'll help you with some problems-you need to solve the rest.
1. 5x - 7 = 43
First: add "7" to both sides...
5x - 7 + 7 = 43 + 7
5x = 50
Sec: isolate "x" > divide both terms by "5"...
5x/5 = 50/5
x = 10
2. Similar to #1-give it a try.
3. - 30 = 3 + 3x
4. 7z - 1 = 23 - 5z
First: add "1" to both sides...
7z - 1 + 1 = 23 - 5z + 1
7z = 24 - 5z
Sec: add "5x" to both sides...
7z + 5z = 24 - 5z + 5z
12z = 24
Third: isolate "z" on one side > divide both terms by "12"
12z/12 = 24/12
z = 2
5. Similar to #1-give it a try.
6. Similary to #1-give it a try.
7. 4x + 5 = 12x - 15x - 2
First: combine "like" terms...
4x + 5 = - 3x - 2
Sec: subtract "5" from both sides...
4x + 5 - 5 = - 3x - 2 - 5
4x = -3x - 7
Third: add "3x" to both sides...
4x + 3x = - 3x + 3x - 7
7x = -7
*Isolate "x" on one side > divide both terms by "7"...
7x/7 = -7/7
x = -1
8. 9(5x - 2) = 27
First: use distribution > multiply the outer term with the terms in parenthesis...
9(5x) + 9(-2) = 27
45x - 18 = 27
Sec: add "18" to both sides...
45x - 18 + 18 = 27 + 18
45x = 45
Third: isolate "x" on one side > divide both terms by "45"...
45x/45 = 45/45
x = 1
2007-01-27 11:57:51 · answer #1 · answered by ♪♥Annie♥♪ 6 · 0⤊ 1⤋
First one... get rid of the -7 by adding 7 to both sides.
5x-7 +7 = 43 + 7
5x = 50 (the -7 and the +7 cancel out)
5x/5 = 50/5 (the factor of x is 5, so divide both sides by that)
x = 10
8x+4=-60
8x+4-4=-60-4
8x=-64
8x/8=-64/8
x=-8
-30=3+3x
-30-3=3+3x-3
-33=3x
-33/3=3x/3
-11=x
7z-1=23-5z (This one is harder...)
7z+5z-1=23-5z+5z (You have to get all of the "z"s on the same side of the equation)
12z-1=23
12z-1+1=23+1
12z=24
12z/12=24/12
z=2
The rest is up to you!
2007-01-27 09:25:19 · answer #2 · answered by Anonymous · 0⤊ 1⤋
Ok this is how you do the first one
5x-7=43
+7 +7 Add seven to both sides
(5x=50)(1/5) Multiply both sides by 1/5
x=10
If you check it then 5(10)-7=43
2007-01-27 09:24:13 · answer #3 · answered by Froggiesmiles 3 · 1⤊ 1⤋
I will just do the last one
9(5x-2) = 45x-18=27
45x=45
x=1
all the others follow the same method
just follow this method and all are very easy to solve
2007-01-27 09:27:42 · answer #4 · answered by sm bn 6 · 0⤊ 1⤋
1. x=10
2.x=-8
3.x=-11
4.z=2
5. a=0
6. x=-7x
7. x=-1
8. x=1
2007-01-27 09:23:40 · answer #5 · answered by bruinfan 7 · 0⤊ 1⤋
Well no I have 8 digit phone number !
2016-05-24 06:31:12 · answer #6 · answered by ? 4 · 0⤊ 0⤋
get the variables and numbers on opposite sides. then divide the number by the coefficient to get the value of the variable.
2007-01-27 09:22:17 · answer #7 · answered by Anonymous · 1⤊ 2⤋
check your textbooks
2007-01-27 09:23:18 · answer #8 · answered by sammy 5 · 0⤊ 1⤋
you know what???? you need to do your own homework!!! pay attention then you'd know!!! geeeeesh!!!!
2007-01-27 09:34:38 · answer #9 · answered by petemeup b 3 · 1⤊ 0⤋