解方程组:4x-2y=14,5x+y=7.
问题描述:
解方程组:4x-2y=14,5x+y=7.
方程组:x+y/3+x-y/2=5,2(x+y)-3(x-y)=6.
可化为:2(x+y)+3(x-y)=( )①
2(x+y)-3(x-y)= ( )②
由①+②,得4(x+y)=( )
所以x+y=( )
由①-②=( )③
由①-②,得6(x-y)=( )
所以x-y=( )④
解由③、④组成的方程组,可求得:x=( ),y=( )
答
方程组:x+y/3+x-y/2=5,2(x+y)-3(x-y)=6.可化为:2(x+y)+3(x-y)=(30 )①2(x+y)-3(x-y)= (6 )②由①+②,得4(x+y)=(36 )所以x+y=( 9) ③由①-②,得6(x-y)=( 24)所以x-y=( 4) ④解由③、④...