a)
[tex]0.3 \times {a}^{2} = 30 \times {b}^{2} [/tex]
[tex] {a}^{2} = \frac{30 \times {b}^{2} }{0.3} [/tex]
[tex] {a}^{2} = 30 {b}^{2} \div \frac{3}{10} [/tex]
[tex] {a}^{2} = 30 {b}^{2} \times \frac{10}{3}[/tex]
[tex] {a}^{2} = \frac{300 {b}^{2} }{3} [/tex]
[tex] {a}^{2} = 100b ^{2} [/tex]
[tex] \frac{ {a}^{2} }{ {b}^{2} } = 100[/tex]
[tex]b) \frac{ {a}^{2} }{ {b}^{2} } = 100[/tex]
[tex]( \frac{a}{b} )^{2} = 100[/tex]
[tex] \frac{a}{b} = \sqrt{100} [/tex]
[tex] \frac{a}{b} = 10[/tex]
