Garis y = ax + b memotong parabola y=x2+x+1 di titik (x1,y1) dan (x2,y2). Jika x1+x2=2 dan x1⋅x2=−1, maka a+b adalah...

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Garis y = ax + b memotong parabola $y=x^2+x+1\;di\;titik\;(x_1,y_1)\;dan\;(x_2,y_2).\;Jika\;x_1+x_2=2\;dan\;x_1\cdot x_2=-1,$ maka a+b adalah...

R. RGFLSATU

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y=ax+b memotong parabola maka:

$x squared plus x plus 1 equals a x plus b x squared plus x minus a x plus 1 minus b equals 0 x squared plus left parenthesis 1 minus a right parenthesis x plus 1 minus b equals 0 c equals 2 minus fraction numerator 1 minus a over denominator 1 end fraction equals 2 minus left parenthesis 1 minus a right parenthesis equals 2 a equals 3 x subscript 1 times x subscript 2 equals negative 1 fraction numerator 1 minus b over denominator 1 end fraction equals negative 1 1 minus b equals negative 1 b equals 2 J a d i space a plus b equals 3 plus 2 equals 5$