Question 316000
"If y varies inversly with x" means that {{{y=k/x}}} where 'k' is some constant number. So if "y=5 when x=7" means that {{{5=k/7}}}. Solve for 'k' to get {{{k=35}}}. So we get the equation {{{y=35/x}}}. Finally, plug in x=4 to get {{{y=35/4=8.75}}}. So you have the correct answer. Good job.