Verified answer

x+y=12,---->x=12-y

xy=35,------->x=35/y

12-y=35/y

12y-y²=36

y²-12y+35=0

∆=(-12)²-4(1)(35)=

144-140=4

√4=2

y=(12±2)/2

y'=10/2=5

y"=17/2=7

(5, 7)

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