ΔABC中,AC=5,BC=6,AD⊥BC于D,AD=4,BE⊥AC于E,求BE长.)2.------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 有唯一解------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 -------------------------╭x+2y=1当m
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![ΔABC中,AC=5,BC=6,AD⊥BC于D,AD=4,BE⊥AC于E,求BE长.)2.------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 有唯一解------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 -------------------------╭x+2y=1当m](/uploads/image/z/3877450-34-0.jpg?t=%CE%94ABC%E4%B8%AD%2CAC%3D5%2CBC%3D6%2CAD%E2%8A%A5BC%E4%BA%8ED%2CAD%3D4%2CBE%E2%8A%A5AC%E4%BA%8EE%2C%E6%B1%82BE%E9%95%BF.%EF%BC%892.------------------------%E2%95%ADax%2B2y%3D1%E5%BD%93a____%E6%97%B6%2C%E6%96%B9%E7%A8%8B%E7%BB%84+%E2%95%B03x%2By%3D3++++%E6%9C%89%E5%94%AF%E4%B8%80%E8%A7%A3------------------------%E2%95%ADax%2B2y%3D1%E5%BD%93a____%E6%97%B6%2C%E6%96%B9%E7%A8%8B%E7%BB%84+%E2%95%B03x%2By%3D3++++-------------------------%E2%95%ADx%2B2y%3D1%E5%BD%93m)
ΔABC中,AC=5,BC=6,AD⊥BC于D,AD=4,BE⊥AC于E,求BE长.)2.------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 有唯一解------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 -------------------------╭x+2y=1当m
ΔABC中,AC=5,BC=6,AD⊥BC于D,AD=4,BE⊥AC于E,求BE长.)
2.
------------------------╭ax+2y=1
当a____时,方程组 ╰3x+y=3 有唯一解
------------------------╭ax+2y=1
当a____时,方程组 ╰3x+y=3
-------------------------╭x+2y=1
当m____时,方程组╰2x+my=2 有无穷多解
ΔABC中,AC=5,BC=6,AD⊥BC于D,AD=4,BE⊥AC于E,求BE长.)2.------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 有唯一解------------------------╭ax+2y=1当a____时,方程组 ╰3x+y=3 -------------------------╭x+2y=1当m
1.∵AD⊥BC
∴S△ABC=BC×AD/2=6×4/2=12
∵BE⊥AC
∴S△ABC=BE×AC/2=BE×5/2
∴BE×5/2=12
∴BE=24/5=4.8 2.(1)a不等于2且a不等于-1时,方程组有唯一一组解
(2)a=-1时方程组无解 (3)a=2时,方程组有无穷多组解
三角形ABC面积S=BC*AD/2=12,ABC面积S也等于AC*BE/2=2.5*BE,因为前面求得S=12,所以BE=12/2.5=4.8 a不等于6;a等于6;m等于4