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September 8th, 2011, 04:18 PM   #1
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2 variable equations

hi to all i am back in college and i have difficulties in math here is my math problem:
my portfolio gained 1.1% overal ,my first bond gained 7.7% and my second lost 3.3%
what is the the initial % invested in my second bond?here is my reflection

x=first bond equation 1 : x+y=100

y=second bond equation 2 : 0.077x-0.033y=1.1

isolate x in equation 2 x=(1.1+0.033y)/0.077 then substitute this value in the equation 1 that give : (1.1+0.033y)/0.077 )+y=100 then i am blocked... i am not able to isolate my y in this equation please help me i am going crazy
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September 8th, 2011, 04:52 PM   #2
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Re: 2 variable equations

x + y = 100
x (0.077) + y (-0.033) = 100 (0.011)

Multiply the first equation by 0.077:
0.077 x + 0.077 y = 7.7
0.077 x - 0.033 y = 1.1

Take the second equation from the first:
0.110 y = 6.6
y = 60 %
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