İf you buy something answer is 1 if u sell something answer is 3:))
5/7*c=5/8
we will divide 5 of both sides at the same time we will multiply 7c *8 two sides
and after that we will see that
8=7*c and then we will divide 7 of both sides and we reach that question
c=8/7
i sent full version of the problem again you can see top of the questions now:) i am sorry its my fault
6/5+3/15=6/5+1/5=7/5
x/7+4+(-4)=2-4 we are sum (-4) two sides and then
x/7=-2 after that we will multiply 7 both of two sides
x/7*7=(-2)*7 and then
x=-14
+35 