Question

Dau coroana. Vă rog ajutați-mă

Answer 1

a).

x+5=0

x=0-5

x=-5

b)

2x-3=6

2x=6+3

2x=9

x=9/2

c)

-x+9=7

-x=7-9

-x=-2

x=2

d)

(înmulțim toată relația cu 2)

3x+5=22

3x=22-5

3x=17

x=17/3

e)

f) 5x-4=0

5x=4

x= 4/5

g)-7x-14=0

-7x=14

-x=2

x=-2

h) (înmulțim toată relația cu 2)

x-14=22

x=22+14

x=36

I) -x-3=5/2

-x=5/2+3

-x=5/2+3/1 (amplificăm 3 pe 1 cu 2 că să putem aduna fractiile)

-x=5/2+6/2

-x=11/2

x=-11/2

j)3x+4=-2

3x=-2+4

3x=-2

x=-2/3

k)

(amplificăm prima fractie cu 3,iar pe a doua cu 5)

18x+10=-165

18x=-165-10

18x=-175

x=-175/18

l)

Answer 2

$\displaystyle a)~x+5=0 \Rightarrow x=0-5 \Rightarrow \boxed{x=-5}\\\\ b)~2x-3=6 \Rightarrow 2x=6+3 \Rightarrow 2x=9 \Rightarrow \boxed{x=\frac{9}{2} }\\\\ c)~-x+9=7 \Rightarrow -x=7-9 \Rightarrow -x=-2 \Rightarrow \boxed{x=2}\\\\ d)~\frac{3}{2} x+\frac{5}{2} =^{2)}11\Rightarrow 3x+5=22 \Rightarrow 3x=22-5 \Rightarrow 3x=17 \Rightarrow \boxed{x=\frac{17}{3} }$

$\displaystyle e)~-\frac{^{3)}1}{5} x+\frac{^{5)}2}{3} =^{15)}8\Rightarrow -3x+10=120\Rightarrow -3x=120-10 \Rightarrow \\\\ \Rightarrow -3x=110 \Rightarrow \boxed{x=-\frac{110}{3}} \\\\ f)~5x-4=0 \Rightarrow 5x=0+4 \Rightarrow 5x=4 \Rightarrow \boxed{x=\frac{4}{5} }$

$\displaystyle g)~-7x-14=0\Rightarrow -7x=0+14 \Rightarrow -7x=14 \Rightarrow x=-\frac{14}{7} \Rightarrow \boxed{x=-2}\\\\ h)~\frac{1}{2}x-^{2)}7=^{2)}11 \Rightarrow x-14=22 \Rightarrow x=22+14 \Rightarrow \boxed{x=36}$

$\displaystyle i)^{2)}-}x-^{2)}3=\frac{5}{2} \Rightarrow -2x-6=5 \Rightarrow -2x=5+6 \Rightarrow -2x=11 \Rightarrow \boxed{x=-\frac{11}{2} }\\\\ j)3x+4=-2\Rightarrow 3x=-2-4 \Rightarrow 3x=-6 \Rightarrow x=-\frac{6}{3}\Rightarrow \boxed{x=-2}$

$\displaystyle k)~\frac{^{3)}6}{5} x+\frac{^{5)}2}{3} =^{15)}-11 \Rightarrow 18x+10=-165 \Rightarrow 18x=-165-10 \Rightarrow \\\\ \Rightarrow 18x=-175 \Rightarrow \boxed{x=-\frac{175}{18} }$

$\displaystyle l)~-\frac{^{6)}3}{5} x+\frac{^{10)}2}{3} =-\frac{^{15)}11}{2} \Rightarrow -18x+20=-165 \Rightarrow -18x=-165-20 \Rightarrow \\\\ \Rightarrow -18x=-185 \Rightarrow \boxed{x=\frac{185}{18} }$