Question

Va rog sa ma ajutați!! Dau coroana!!!!!!!!

Answer 1

Răspuns:

a) 2x+3x+5=13   5x+5=13  5x=13-5   5x=8  x= 8/5

b) 3x-2x=16   x=16

3x+3+x=15   4x=15-3=12   4x=12=> x= 12:4=3   x=3

5x+6=-9   5x=-9-6   5x=-15  x=-15:5=-3   x=-3

$\frac{3}{4} - \frac{1}{8}$= $\frac{2*3 -1}{8}$= $\frac{6-1}{8}$=5/8  ( se aduce la acelasi numitor)

$\frac{7}{3} +\frac{4}{5} +\frac{22}{15}$ = $\frac{7*5}{15} + \frac{4*3}{15} +\frac{22}{15}$= $\frac{35+12+22}{15}$= $\frac{69}{15}$

$\frac{2}{15} +\frac{1}{12}$=$\frac{2*4}{60} +\frac{1*5}{60}$= $\frac{8+5}{60}$=$\frac{13}{60}$                        12=$2^{2}$*3    15=3*5   n.c= 4*3*5 =12*5=60

$\frac{13}{60}$x $\frac{60}{13}$ - $\frac{1*2}{7}$= 1- $\frac{2}{7}$= $\frac{7-2}{7} =\frac{5}{7}$

$\frac{1}{3} + \frac{7}{6} -\frac{5}{18} = \frac{6+21-5}{18} = \frac{22}{18} =\frac{11}{9}$

$\frac{2}{15} *\frac{15}{2}$= 1

$\frac{7}{16} :\frac{21}{8} =\frac{7}{16} *\frac{8}{21} =\frac{1}{6}$