M-n=12 m-n=12
m+n=6 сложим почленно m*n=6
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2m=18 m=12+n
m=9 (12+n)*n=6
n=6-m=6-9=-3 12n+n²=6
1/m- 1/n=1/9 - (-1/3)= 1/9 +1/3= 4/9 n²+12n-6=0
D=144+24=168=2√42
n₁=(-12+2√42)/2=-6+√42 m₁=6+√42
n₂=(-12-2√42)/2=-6-√42 m₂=6-√42