若4X﹣3Y-6Z=0,X+2Y-7Z=0,(XYZ不等于0),求(5X^2+2Y^2-Z^2)/(2X^2-3y^2-10Z^2)的值?
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![若4X﹣3Y-6Z=0,X+2Y-7Z=0,(XYZ不等于0),求(5X^2+2Y^2-Z^2)/(2X^2-3y^2-10Z^2)的值?](/uploads/image/z/320309-53-9.jpg?t=%E8%8B%A54X%EF%B9%A33Y-6Z%3D0%2CX%2B2Y-7Z%3D0%2C%EF%BC%88XYZ%E4%B8%8D%E7%AD%89%E4%BA%8E0%EF%BC%89%2C%E6%B1%82%EF%BC%885X%5E2%2B2Y%5E2-Z%5E2%EF%BC%89%2F%282X%5E2-3y%5E2-10Z%5E2%29%E7%9A%84%E5%80%BC%3F)
若4X﹣3Y-6Z=0,X+2Y-7Z=0,(XYZ不等于0),求(5X^2+2Y^2-Z^2)/(2X^2-3y^2-10Z^2)的值?
若4X﹣3Y-6Z=0,X+2Y-7Z=0,(XYZ不等于0),求(5X^2+2Y^2-Z^2)/(2X^2-3y^2-10Z^2)的值?
若4X﹣3Y-6Z=0,X+2Y-7Z=0,(XYZ不等于0),求(5X^2+2Y^2-Z^2)/(2X^2-3y^2-10Z^2)的值?
4X﹣3Y-6Z=0 (1) X+2Y-7Z=0 (2) (1) - (2) * 4 ==> -11y + 22z = 0 ==> y = 2Z (1) * 2 + (2) * 3 ==> 11x - 33z =0 ==> x = 3Z (5X^2+2Y^2-Z^2)/(2X^2-3y^2-10Z^2) = [5 * (3z)^2 + 2 * (2z)^2 - z^2)] / [ (2 * (3z)^2 - 3 * (2z)^2 - 10z^2] = [ 5 * 9 + 2 * 4 - 1] / [2 * 9 - 3 * 4 - 10] = [45 + 6 - 1] / [18 - 12 - 10] = 50 / (-4) = - 25/2