Mi aiutate

204)

a. $\small \dfrac{\cancel7^1}{\cancel{33}_3}×\dfrac{\cancel{44}^4}{\cancel{35}_5} = \dfrac{1}{3}×\dfrac{4}{5} = \dfrac{4}{15}$

b. $\small \dfrac{15}{16}×\dfrac{\cancel{12}^4}{\cancel{45}_{15}} = \dfrac{\cancel{15}^1}{\cancel{16}_4}×\dfrac{\cancel4^1}{\cancel{15}_1} = \dfrac{1}{4}×\dfrac{1}{1} =\dfrac{1}{4}$

c. $\small \dfrac{\cancel{49}^7}{\cancel{13}_1}×\dfrac{\cancel{26}^2}{\cancel{63}_9} = \dfrac{7}{1}×\dfrac{2}{9} = \dfrac{14}{9}$

d. $\small \dfrac{\cancel{9}^1}{\cancel{20}_5}×\dfrac{\cancel{12}^3}{\cancel{18}_2} = \dfrac{1}{5}×\dfrac{3}{2} = \dfrac{3}{10}$

203)

a. $\small \dfrac{5}{\cancel{24}_8}×\dfrac{\cancel{15}^5}{2} = \dfrac{5}{8}×\dfrac{5}{2} = \dfrac{25}{16}$

b. $\small \dfrac{\cancel4^1}{\cancel7_1}×\dfrac{\cancel{56}^8}{\cancel{12}_3} = \dfrac{1}{1}×\dfrac{8}{3} = \dfrac{8}{3}$

c. $\small \dfrac{\cancel9^1}{\cancel4_2}×\dfrac{\cancel{10}^5}{\cancel{27}_3} = \dfrac{1}{2}×\dfrac{5}{3} = \dfrac{5}{6}$

d. $\small \dfrac{\cancel{25}^5}{\cancel{14}_2}×\dfrac{\cancel7^1}{\cancel{10}_2} = \dfrac{5}{2}×\dfrac{1}{2} = \dfrac{5}{4}$

206)

a. $\small \dfrac{3}{\cancel{2}_1}×\dfrac{\cancel{4}^2}{5} ×\dfrac{7}{8} = \dfrac{3}{1}×\dfrac{\cancel2^1}{5}×\dfrac{7}{\cancel8_4} = \dfrac{3}{1}×\dfrac{1}{5}×\dfrac{7}{4} = \dfrac{21}{20}$

b. $\small \dfrac{\cancel{14}^7}{\cancel{36}_{18}}×\dfrac{18}{7} ×\dfrac{\cancel6^3}{\cancel8_4} = \dfrac{\cancel7^1}{\cancel{18}_1}×\dfrac{\cancel{18}^1}{\cancel7_1}×\dfrac{3}{4} = \dfrac{1}{1}×\dfrac{1}{1}×\dfrac{3}{4} = \dfrac{3}{4}$

206)

3/2 x 4/5 x 7/8 = (3 x 4 x 7) /(2 x 5 x 8);

semplifichi 4 con 8, resta 1/2;

(3 x 1 x 7) /(2 x 5 x 2) = 21/20;

14/36 x 18/7 x 6/8 ; 

possiamo prima semplificare 14/36 = 7/18; dividendo per 2;

6/8 = 3/4; dividendo per 2;  così resta:

7/18 x 18/7 x 3/4 = (7 x 18 x 3) /18 x 7 x 4);

si semplifica 7 con 7;   7/7 = 1/1;   

18 con 18; 18/18 = 1/1;

(1 x 1 x 3) / (1 x 1 x 4) = 3/4.

Ciao @marialuigia

a

5/24 * 15/2 = 5/8 * (5*2) = 25/16

b

4/7 * 56/12 = 1*8 / (1*3) = 8/3 

c

9/4 * 10/27 = 1/2 * (5/3) = 5/6

d

25/14 * 7/10 = 5/2 * (1/2) = 5/4

a

7/33 * 44/35 = 1/3 * 4/5 = 4/15

b

15/16 * 12/45 = 1/4 * 3/3 = 1/4

c

49/13 * 26/63 = 7/1 * 2/9 = 14/9

d

9/20 * 12/18 = 9/20 * 2/3 = 3/10

a

3/2 * 4/5 * 7/8 = 3*7 / (2*5*2) = 21/20

b

14/36 * 18/7 * 6/8 = 2/2 * 1/1 *3/4 = 3/4

Daiiiiii, sono esercizi facili, provo la a e b dell'es.206

a.3/2*4/5*7/8=84/80;  semplificato diventa:21/20

b.14/36*18/7*6/8=1512/2016; semplificato diventa:3/4

TEORIA: Per fare le moltipliche con le frazioni, basta che semplifichi a croce così non farai numeri grandi.

Ciao @Marialuigia