【用戶】peter971016
【年級】小一下
【評論內容】因要與X軸圍成三角形面積,所以設Y = 02x - 3y = 12 設 Y = 0, x = 65x + 3y = 9 設 Y = 0, x = 9/5求二方程式交點2x - 3y = 125x + 3y = 9二式相加7x = 21, x = 3, y = -2底 = 6 - 9/5 = 21/5高 = | y| = |-2| = 2面積 = 21/ 5 x 2 x 1/2 = 21/5