Question

Can anybody help me with this?

Answer 1

`\bf 7* \cfrac{n}{4}>7\implies \cfrac{7n}{4}>7\implies \cfrac{n}{4}>\cfrac{7}{7}\implies \cfrac{n}{4}>1\implies n>4`

whatever value "n" is, it must be greater than 4, cannot be 4 or less.

notice that simplifying inequalities is hardly any different than doing equalities, there's just one difference when using a negative factor.

`\bf 7*\cfrac{a}{b}=7\implies \cfrac{7a}{b}=7\implies \cfrac{a}{b}=\cfrac{7}{7}\implies \cfrac{a}{b}=1\implies a=b`

whatever value "a" might be, it must be equal to "b".