[tex]1) {(a - 2b)}^{2} [/tex]
[tex] = {a}^{2} - 2 \times a \times 2b + (2 {b})^{2} [/tex]
[tex] = {a}^{2} - 4ab + 4 {b}^{2} [/tex]
[tex] = {a}^{2} - 4(ab - {b}^{2} )[/tex]
[tex]2) |2 - 1| + |2| + |3 - 2| + {2}^{2} [/tex]
[tex] = |1| + 2 + |1| + 4[/tex]
[tex] = 1 + 2 + 1 + 4[/tex]
[tex] = 8[/tex]
[tex]3) \sin(30) + \cos(60) - \tan(30) [/tex]
[tex] = \frac{1}{2} + \frac{1}{2} - \frac{ \sqrt{3} }{3} [/tex]
[tex] = \frac{1 + 1}{2} - \frac{ \sqrt{3} }{3} [/tex]
[tex] = \frac{2}{2} - \frac{ \sqrt{3} }{3} [/tex]
[tex] = 1 - \frac{ \sqrt{3} }{3} [/tex]
[tex] = \frac{3}{3} - \frac{ \sqrt{3} }{3} [/tex]
[tex] = \frac{3 - \sqrt{3} }{3} [/tex]
