Question

Dau coroana, macar la unele ajutați-mă, vreau si calculele​

Answer 1

Răspuns:

ex 1.

$\sqrt{0.5} = \sqrt{ \frac{5}{10} } = \sqrt{ \frac{1}{2} } = \frac{ \sqrt{1} }{ \sqrt{2} } = \frac{1}{ \sqrt{2} }$

raspuns corect: D

ex 2

$- \frac{1}{7} = - \frac{7}{1} = - 7$

raspuns corect: B

ex 3

$0.(6) - 1 = \frac{6}{9} - 1 = \frac{2}{3} - 1 = \frac{2 - 1 \times 3}{3} = - \frac{1}{3}$

raspuns corect: D

ex 7

linia mijlocie = (AD +CD ):2 =(9+13):2=22:2 = 11 cm

raspuns corect: B

ex. 5

$\sqrt{5} \times + 3 = 8 \\ \sqrt{5} \times = 5 \\ x = \frac{5}{ \sqrt{5} } \\ x = \frac{5 \sqrt{5} }{5} \\ x = \sqrt{5}$

raspuns corect: A

ex. 6

$\frac{2}{ \sqrt{6} } = \frac{2 \sqrt{6} }{ \sqrt{6 \times \sqrt{6} } } = \frac{2 \sqrt{6} }{6} = \frac{ \sqrt{6} }{3}$

raspuns corect: C

ex. 9

AB^2 +AC^2 = BC^2 (T. lui Pitagora)

3^2 + AC^2 =5^2

9+AC^2=25

AC^2=16

AC=4

Aria=(AB×AC):2=(3×4):2=12:2=6 cm^2

raspuns corect: D