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28 votes
28 votes
Helpppppppppppppppppppppppp

Helpppppppppppppppppppppppp-example-1
User Christopher Beck
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2.7k points

2 Answers

20 votes
20 votes
i’d say 21 and -1 :)
21 * -1 = -21
21 - 1 = 20
User Diceyus
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2.8k points
15 votes
15 votes


xy =-21~~.....(i)\\\\x+ y=20~~....(ii)\\\\\text{From equation (i):}\\\\xy = -21 \implies y = -\frac{21}x~~.....(iii)\\\\\text{Substitute y in equation (ii):}\\\\x - \frac{21}x = 20\\\\\implies x^2 -20x -21= 0\\\\\implies x^2 - 21x + x-21=0\\\\\implies x(x-21) +(x-21) =0\\\\\implies (x+1)(x-21)=0\\\\\implies x = -1 ~~\text{or}~~ x =21\\\\\text{Substitute x in equation (iii):}\\\\y = 21 ~~ \text{or}~~ y = -1\\\\\text{Hence,}~ (x,y)=(21,-1) ~~ \text{or}~~ (x,y) = (-1,21)

User VasilKanev
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2.7k points