Question

1 Calculati:
(a-2b)la 2 =
(2b-1) la 2 =

2 Pentru x=2, calculeaza expresia |x-1|+|x|+|3-x|+x la 2

3 Calculati sin 30°+cos 60°-tg30°

Va rog ajutati.ma pana la 23:10 va roggg !!!

Answer 1

$1) {(a - 2b)}^{2}$

$= {a}^{2} - 2 \times a \times 2b + (2 {b})^{2}$

$= {a}^{2} - 4ab + 4 {b}^{2}$

$= {a}^{2} - 4(ab - {b}^{2} )$

$2) |2 - 1| + |2| + |3 - 2| + {2}^{2}$

$= |1| + 2 + |1| + 4$

$= 1 + 2 + 1 + 4$

$= 8$

$3) \sin(30) + \cos(60) - \tan(30)$

$= \frac{1}{2} + \frac{1}{2} - \frac{ \sqrt{3} }{3}$

$= \frac{1 + 1}{2} - \frac{ \sqrt{3} }{3}$

$= \frac{2}{2} - \frac{ \sqrt{3} }{3}$

$= 1 - \frac{ \sqrt{3} }{3}$

$= \frac{3}{3} - \frac{ \sqrt{3} }{3}$

$= \frac{3 - \sqrt{3} }{3}$

Answer 2

1.a^2-4ab+4b^2
4b^2-4b+1
conform (a-b)^2=a^2-2ab+b^2
2.|2-1|+|2|+|3-2|+2^2=
1+2+1+4=8
3.sin 30°=1/2
cod 60°=1/2
tg30°=sin 30°/cos 30°
tg3O°=1/2:√3/2=1/√3=√3/3
1/2+1/2-√3/3=2/2-√3/3=1-√3/3