2x +3y = 5 x² +3xy = 4 Okay, so I substitute y = -2/3x +5/3 x² +3x(-2/3x +5/3) -4 I get '3x² +5x -4' It doesn't factorise, so I use the formula and answers are decimals, but the answers in textbook are 1,1 and 4,-1 So, what did I do wrong?
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Originally Posted by quadling 2x +3y = 5 x² +3xy = 4 Okay, so I substitute y = -2/3x +5/3 x² +3x(-2/3x +5/3) -4 I get '3x² +5x -4' It doesn't factorise, so I use the formula and answers are decimals, but the answers in textbook are 1,1 and 4,-1 So, what did I do wrong? Check the coefficient of the x^2 again. x^2 - 2x^2 is.... -Dan
ffs. sorry. thanks.
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