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Solve 5x^2 - 7x + 2 = 0 by completing the square. What is the constant added on to form the perfect square trinomial?

2 Answers

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5x^(2)-7x+2=0 \\ \\ 9x^(2)-9x+ (9)/(4) - 4x^(2)+2x- (1)/(4) \\ \\ (3x- (3)/(2) )^(2)-(2x-(1)/(2) )^(2) \\ \\ (3x- (3)/(2) +2x- (1)/(2) )(3x- (3)/(2)-2x+ (1)/(2) ) \\ \\ (5x-2)(x-1)=0 \\ \\ 5x-2=0 \ \vee \ x-1=0 \\ \\ 5x=2 \ \vee \ x=1 \\ \\ x= (2)/(5) \ \vee \ x=1 \\ \\ \boxed{\boxed{x\in \lbrace (2)/(5),1 \rbrace }}
User Rob Worsnop
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2 votes

Answer: 49/100 is correct

( wrong answers bother me..)

User Bovard
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