a+b=90, a=90-b
[tex] \frac{1}{5}a-2= \frac{1}{3}b, \frac{1}{5}(90-b)-2= \frac{1}{3}b [/tex]
mai departe scriu fractiile sub forma (x/y)
(90/5)-(1/5)b-2=(1/3)b
(90/5)-2=(1/3)b+(1/5)b
(90/5)-(10/5)=(5/15)b+(3/15)b
(80/5)=(8/15)b
(80/5):(8/15)=b
(80/5)*(15/8)=b
30=b
a=90-30=60
unghiul a(1)=60 grade
unghiul b(2)=30 grade
60:5=12
30:3=10
primul cu 2 grade mai mare