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標題:

Quadratic equation!! Thx=]]

發問:

Ans:54

最佳解答:

Put y=0, 0 = -2x^2 + 18 0 = 2x^2 - 18 0 = x^2 - 9 x = 3 OR x = -3 所以 A(-3,0) B (3,0) Put x=0, y = 18 所以 C(0,18) AO = 3 BO = 3 CO = 18 Area of ABC = AB * CO * 0.5 = (3 + 3)(18)(0.5) = 54..... Hope can help!

其他解答:

• Grestest Common Divisor {GCD}
• 關於香港60位直選選民的名字@1@
• 中一ｍａｔｈｓ

• Grestest Common Divisor {GCD}
• 關於香港60位直選選民的名字@1@
• 中一ｍａｔｈｓ

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To solve this question, you need to find the x-intersect and y-intersect. Solution: put x=0, y=-2(0)^2+18 = 18 put y=0, 0= -2x^2 +18 2x^2=18 x^2 = 9 x = 3 or -3 The area of triangle ABC = [3-(-3)](18)/2 = 54 sq. units