[tex] {a}^{2} - {b}^{2} = 180[/tex]
[tex]a - b = 10[/tex]
[tex] {a}^{2} - {b}^{2} = (a + b)( a- b)[/tex]
[tex](a + b)(a - b) = 180[/tex]
[tex](a + b) \times 10 = 180[/tex]
[tex]a + b = 180 \div 10[/tex]
[tex]a + b = 18[/tex]
[tex]a = 18 - b[/tex]
[tex]18 - b - b = 10[/tex]
[tex] - b - b = 10 - 18[/tex]
[tex] - 2b = - 8 \: | \div ( - 2)[/tex]
[tex]b = 4[/tex]
[tex]a = 18 - b[/tex]
[tex]a = 18 - 4[/tex]
[tex]a = 14[/tex]