Question

求解这道二元一次方程

0.09*x-0.09*y=[(1.09*x)/1.03]*0.03
(x-y-1)*0.1=(1.09*x)/1.03-1.09*y-1]*0.05
最后求x和y 的值

Answer 1

0.09*x-0.09*y=[(1.09*x)/1.03]*0.03①
(x-y-1)*0.1=[(1.09*x)/1.03-1.09*y-1]*0.05②
①两边都除以0.03，得3x-3y=109x/103,
两边都乘以103，得309x-309y=109x,
200x=309y,x=309y/200,③
②两边都除以0.05，得2x-2y-2=109x/103-1.09y-1,
两边都乘以103，得206x-206y-103=109x-112.27y,
97x-93.73y=103,④
把③代入④*200，得11227y=20600,
所以y=200/109,
代入③，得x=309/109.

Answer 2

x=1+2/1.09
y=2/1.09