Question 334974
0.63B + 0.37N = -8.4 
0.56B + 0.44N = -6.6
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Multiply thru each equation by 100 to get rid of the decimals:
63B + 37N = -840
56B + 44N = -660
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Multiply thru the 1st equation by 56
Multiply thru the 2nd equation by 63
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56*63B + 56*37N = 56*-840
63*56B + 63*44N = 63*-660
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Subtract the 1st equation from the 2nd and solve for "N":
700N = 5460
N = 7.8
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Substitute into 56B+44N=-660 and solve for "B":
56B+44(7.8)=-660
56B = 1003
B = 17.9143
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Cheers,
Stan H.