SOLUTION: solve each proportion. 2/7 = x/-42 5/12 = (x+1)/4 (n+8)/-5=(n-3)/-1 (5-w)/(3+w)=13/12 any idea on these? im absolutely clueless...

Algebra ->  Algebra  -> Polynomials-and-rational-expressions -> SOLUTION: solve each proportion. 2/7 = x/-42 5/12 = (x+1)/4 (n+8)/-5=(n-3)/-1 (5-w)/(3+w)=13/12 any idea on these? im absolutely clueless...      Log On

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Question 7301: solve each proportion.
2/7 = x/-42
5/12 = (x+1)/4
(n+8)/-5=(n-3)/-1
(5-w)/(3+w)=13/12
any idea on these?
im absolutely clueless...
Answer by bonster(299) About Me  (Show Source):
You can put this solution on YOUR website!
#1) 2%2F7 = x%2F-42
Multiply both sides by -42
%28-42%29%2F1*2%2F7 = x%2F-42*%28-42%29%2F1
(-6)(2)=x
-12=x




#2) 5%2F12 = %28x%2B1%29%2F4
Multiply both sides by 12
%2812%29%2F1*5%2F12 = %28x%2B1%29%2F4*%2812%29%2F1
reduce
5=(x+1)(3)
5=3x+3
subtract 3 from both sides
5-3=3x+3-3
2=3x
multiply both sides by 1%2F3
1%2F3*2=3*1%2F3
x=2%2F3



#3) %28n%2B8%29%2F-5=%28n-3%29%2F-1
Cross multiply
(n+8)(-1)=(-5)(n-3)
-n-8=-5n+15
add 5n to both sides
(-n-8)+5n=(-5n+15)+5n
4n-8=15
add 8 to both sides
(4n-8)+8=(15)+8
4n=23
Multiply both sides by 1%2F4
1%2F4(4n)=(23)*1%2F4
n=23%2F4 or 53%2F4




#4) %285-w%29%2F%283%2Bw%29=13%2F12
cross multiply"
(5-w)(12)=(3+w)(13)
60-12w=39+13w
subtract 39 from both sides
21-12w=13w
add 12w to both sides
21=25w
multiply both sides by 1%2F25
21%2F25=w