.有甲乙两桶汽油,从甲桶中倒出1/3给乙桶后,又从乙桶中倒出20%给甲桶,这是两桶油都各有24千克.原来甲乙两桶各有油多少千克?

原来甲乙各有 x ,y 千克.2x/3 + 0.2(x/3 + y) = 24 (1)0.8(x/3 + y) = 24 (2)(1) × 15 ,(2) × 15 ,得11x + 3y = 360 (3)4x+ 12y = 360 (4)(3) × 4 - (4) ,得40x = 1080x = 27 千克y = 21 千克