Question

dau coroana......si inima ​

Answer 1

In genul acesta de exercitiu putem inmultii termenii pe diagonala astfel:

a)

$\frac{6}{5}= \frac{n}{25}=\\\\5*n=6*25\\\\5n=150\\n=150:5\\n=30$

b)

$\frac{n}{12}= \frac{4}6}=\\\\n*6=12*4\\\\6n=48\\n=48:6\\n=8$

c)

$\frac{24}{n}= \frac{14}{28}=\\\\n*14=24*28\\\\14n=672\\n=672:14\\n=48$

d)

$\frac{60}{40}= \frac{9}{n}=\\\\60*n=40*9\\\\60n=360\\n=360:60\\n=6$

e)

$\frac{n}{3}= \frac{48}{n}=\\\\n*n=3*48\\\\n^{2} =144\\n=\sqrt{144} \\n=12$

f)

$\frac{4}{n+1}= \frac{24}{30}=\\\\24*(n+1)=4*30\\24n+24=120\\24n=120-24\\24n=96\\n=96:24\\n=4$

g)

$\frac{2n+1}{7}= \frac{15}{21}=\\\\21*(2n+1)=15*21\\42n+21=315\\42n=315-21\\42n=294\\n=294:42\\n=7$

h)

$\frac{3n-2}{n}= \frac{5}{2}=\\\\2*(3n-2)=5*n\\6n-4=5n\\6n-5n=4\\n=4$

i)

$\frac{n}{n+1}= \frac{12}{15}=\\\\n*15=12*(n+1)\\15n=12n+12\\15n-12n=12\\3n=12\\n=12:3\\n=4$