Question

Va rog mult dau coroana +puncte urgenttt

Answer 1

Răspuns:

Explicație pas cu pas:

8.

$(2^5 + 2^2):6 + 2^2 + 2^1 + 2^0 - 1^{2015} =$

$=(32 + 4):6 + 4 + 2 + 1 - 1 =$.

$=36:6 +6 =$

$= 6 + 6 =$

$= 12$

9.

$a = [2,(6) + 1,2(3)]:0,026 + 0,19:0,01 =$

$=( \frac{24}{9}+\frac{111}{90}): \frac{26}{1000} + \frac{19}{100} :\frac{1}{100} =$

$=( \frac{8}{3}+\frac{37}{30}): \frac{13}{500} + \frac{19}{100}*100=$

$=( \frac{80}{30}+\frac{37}{30}): \frac{13}{500} + \frac{19}{100}*100=$

$=\frac{117}{30}*\frac{500}{13} + 19 =$

$=\frac{3*3*13}{10*3}*\frac{50*10}{13} + 19 =$

$=3*50+ 19 =$

$= 150 + 19 =$

$= 169 =$

$= 13^2$

este patrat perfect.

10.

a)

17 dm = 1,7 m

200 cm = 2 m

volumul = 0,3 * 1,7  * 2 = 1,02 m cubi.

b)

1 m cub = 1000 litrii.

1,02*1000/0,5 = 2040 sticle

11

Notam cu x, y si z cele trei numere

avem:

(x + y + z)/3 = 14

si

x = y + 7

z = 3*y

(y + 7 + y + 3*y)/3 = 14

(5*y + 7)/3 = 14

5*y + 7 = 14*3

5*y + 7 = 42

5*y = 42 - 7

5*y = 35

y = 35/5

y = 7

Si atunci

x= y + 7 = 7 + 7 = 14

z = 3*y = 3*7 = 21