Răspuns:
Explicație pas cu pas:
[tex]\frac{a}{5} =\frac{b}{3} \\3a=5b\\\\a=\frac{5b}{3}[/tex]
a)
[tex]\frac{2a+b}{3b-a} =\frac{\frac{5b}{3} +b}{3b-\frac{5b}{3} }\\\frac{\frac{5b+3b}{3} }{\frac{9b-5b}{3} } = \frac{\frac{8b}{3} }{\frac{4b}{3} } = \frac{8b}{3}*\frac{3}{4b}= 2[/tex]
b)
[tex]a+b = 160\\\frac{5b}{3} +b = 160\\5b+3b = 480\\8b=480\\b= 60\\a= \frac{5b}{3} \\a= 100[/tex]
c)
[tex]a*b = 135\\\frac{5b}{3} *b = 135\\\frac{5b^{2} }{3} =135\\5b^{2}= 405\\b^{2}=81\\b=9\\a=\frac{5b}{3}\\a= 15\\Ma= \frac{a+b}{2} = \frac{9+15}{2} =12[/tex]
