Given the inequality
[tex]21y>84[/tex]We solve it as following:
[tex]21y>84\rightarrow\frac{21y}{21}>\frac{84}{21}\rightarrow y>4[/tex]Thereby, y has to be greater than 4.
[tex]y>4[/tex]As an interval,
[tex]y\in(4,\infty)[/tex]NOTE: Remember that dividing or multiplying an inequality by a negative number turns it around! Here we divided by 21, so it stayed the same.
