[질문] 쎈 7가 1680 번부터 1692번까지정답좀

1680~20x=60, x=3 /2(8+x)=28, x=6/4x+2=30, x=7/3000-800x=600, x=3/(x+4)살/x+(x+4)=32/형：18살, 동생：14살/3분의x시간/2분의x시간/x/20g/(250+x)g