Question

Aflati nr nat x si y astfel incat fiecare dintre urmatoarele egalitati sa fie adevarate:

a)$\frac{6}{8}$=$\frac{3}{y}$
b)$\frac{x+1}{15}$=$\frac{2}{3}$
c)$\frac{7x+21}{x+2}$=$\frac{x+3}{5}$

Simplificati fractiile urmatoare astfel incat sa obtineti fractii ireductibile:

a)$\frac{a3+3a}{7a+a7}$    ( cu bara deasupra la a3+3a si la 7a+a7)
b)$\frac{abc+bca+cab}{5a+5b+5c}$     (cu bara deasupra la abc+bca+cab)
                   
            VA ROG AJUTATI-MA!!!!!!!!!!!!!

Answer 1

a)6y=24⇔y=4
b)(x+1)·3=30⇔x+1=10⇔x=9
c)(7x+21)·5 = (x+2)·(x+3) ⇔ 35x+105 = x·(x+3)+2(x+3) ⇔ 35x+105 = x²+3x+2x+6 ⇔ 35x+99 = x²+5x ⇔ 30x = x ² ⇔ 30x = x·x ⇔ 30 = x

a)10a+3+30+a/70+a+10a+7=11a+33/77+11a=11(a+3)/11(7+a)= a+3/7+a
b)100a+10b+c+100b+10c+a+100c+10a+b/5(a+b+c)=111a+111b+111c/5(a+b+c)=111(a+b+c)/5(a+b+c)=111/5