5(r-4) = -5(r-4)
This on is also giving me trouble:
7/2x +15 = x + 15/2
更新1:
i made a typo the question is 7/2x+5 = x+15
More help with math?
2008-04-26 5:24 pm
can anyone help me with this problem? I know it may seem simple but i can't seem to figure it out... :(
5(r-4) = -5(r-4)
This on is also giving me trouble:
7/2x +15 = x + 15/2
5(r-4) = -5(r-4)
This on is also giving me trouble:
7/2x +15 = x + 15/2
回答 (5)
2008-04-26 5:54 pm
✔ 最佳答案
1)5(r - 4) = -5(r - 4)
5r - 20 = -5r + 20
5r + 5r = 20 + 20
10r = 40
r = 40/10
r = 4
2)
(7/2)(x) + 15 = (x + 15)/2
2(7x/2 + 15) = 2(x + 15)/2
7x + 30 = x + 15
7x - x = -30 + 15
x = -15/6
x = -2 1/2 (-2.5)
2008-04-27 1:26 am
Question 1
5r - 20 = - 5r + 20
10 r = 40
r = 4
Question 2
Is badly presented in that it can be read in a number of ways.
Brackets must be used to clarify :-
Do you mean :-
7 / (2x + 15) = (x + 15) / 2
OR
7/(2x) + 15 = x + (15/2)
OR
7 / (2x + 15) = x + (15/2)
OR
???????????
Will pass on this one if you don`t mind.
5r - 20 = - 5r + 20
10 r = 40
r = 4
Question 2
Is badly presented in that it can be read in a number of ways.
Brackets must be used to clarify :-
Do you mean :-
7 / (2x + 15) = (x + 15) / 2
OR
7/(2x) + 15 = x + (15/2)
OR
7 / (2x + 15) = x + (15/2)
OR
???????????
Will pass on this one if you don`t mind.
2008-04-27 12:37 am
5(r-4)=-5(r-4)
r-4 = -(r-4)
r-4 = -r +4
2r -4 + 4
2r = 8
r = 4
ii) 7/2x +15 = x +7.5
7 +30x = 2x^2 +15x
2x^2 -15x - 7 = 0
then use quadratic formula,
unless u mean 3.5x +15 = x +7.5
2.5x = -7.5
x = -3
r-4 = -(r-4)
r-4 = -r +4
2r -4 + 4
2r = 8
r = 4
ii) 7/2x +15 = x +7.5
7 +30x = 2x^2 +15x
2x^2 -15x - 7 = 0
then use quadratic formula,
unless u mean 3.5x +15 = x +7.5
2.5x = -7.5
x = -3
2008-04-27 12:36 am
[6]
5(r-4)= -5(r-4)
5r-20= = -5r+20
5r+5r=20+20
10r=40
r=40/10=4
7x/2 +15=x + 15/2
7x+30=2x+15 [multiplying both sides by 2]
7x-2x=15-30
5x= -15
x= -15/5 = -3
5(r-4)= -5(r-4)
5r-20= = -5r+20
5r+5r=20+20
10r=40
r=40/10=4
7x/2 +15=x + 15/2
7x+30=2x+15 [multiplying both sides by 2]
7x-2x=15-30
5x= -15
x= -15/5 = -3
2008-04-27 12:35 am
5(r-4) = -5(r-4)
5r-20=-5r+20
5r+5r=20+20
10r=40
r=40/10
r=4
The second question seems a bit confusing :S i can try it on paper and pencil and let you knwo the answer if i figure it out in like a few min
5r-20=-5r+20
5r+5r=20+20
10r=40
r=40/10
r=4
The second question seems a bit confusing :S i can try it on paper and pencil and let you knwo the answer if i figure it out in like a few min
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