Question

Vă rog e urgent Cine știe? îmi trebuie toate!!!

Answer 1

Răspuns:

1. 0,5 *x = $\frac{2*3+1}{3} * \frac{1*7+3}{7}$

$\frac{5x}{10}$ = $\frac{7}{3} * \frac{10}{7}$       $\frac{5x}{10}$ = $\frac{10}{3}$  => x= $\frac{10}{3} *\frac{5}{10}$  = $\frac{5}{3}$

x= $\frac{5}{3}$

2.    10/998  = 0.01002

3. a+b+c= 560

$\frac{a}{2} = \frac{b}{11} =\frac{c}{7}$= k   => a= 2k    b= 11k    c= 7k

2k+ 11k+7k= 560

20k = 560      k= 560/20= 28

a= 2*28= 56    

b= 11*28= 308

c= 7*28= 196

4.

400- 36= 364 seminte incoltite

p%= 364*100/400= 91 %

5. 48 * $\frac{15}{100}$= 48* $\frac{3}{20}$= $\frac{48*3}{5*4}$= $\frac{12*3}{5} =\frac{36}{5}$

48- $\frac{36}{5}$= $\frac{48*5-36}{5} = \frac{240-36}{5}$= 204:5= 40, 8 lei pretul dupa reducere

6.  4*( 3x-y) = 5*(2x+y)

12x- 4y = 10 x + 5y

12x-10x= 5y+4y

2x= 9y   => $\frac{x}{y} =\frac{2}{9}$