Deyang City 2012-2013 Mathematics Answers for the Final Examination of the Ninth Grade Volume 1

Mathematics reference answers: 1. ADCAC ABCDB 2. 11. 20. (1) x1=3, x2=1, (2) x ?2 ? 3; 21. (1) 1, (2) 1/6; 22. The coordinates of point A? (-4, 2), the coordinates of point B? (-1, 3); 23 (1). Assume that the length of one side of the rectangle is x meters, and x(20-x)=100 Obtain: x1=x2=10, so it can be achieved. Design it as a square with a side length of 10m; (2) From x(20-x)=110, we get: (2) In ∵equilateral △ABC, AM is the midline on side BC, ∴AM⊥BC, ∠ACB=60°, ∠CAD=30°. It can be known from the rotation: ∠CBE=∠CAD=30°. If CH⊥BE is set at point H, then PQ=2HQ. Connect CQ, then CQ=CN=5. In In Rt△CBH, ∠CBH=30°, ∴CH=1/2BC=4. In Rt△CHQ, from the Pythagorean theorem, we get HQ ?