5. unghiurile complementare au suma egala cu 90°
m(A)+m(B)=90°,m(A)=90°-m(B)
m(A)=80*m(B)/100=4*m(B)/5 egalam
90-m(B)=4*m(B)/5, numitor comun 5
450-5m(B)=4m(B)
9m(B)=450
m(B)=450/9=50°
m(A)=90°-50°=40°
6.a) notam cu e nr de exercitii
prima zi e*20/100=2*e/10
a doua zi 3*e/10
a treia zi e-2*e/10-3e/10=5*e/10 deci cel mai mult a lucrat in a treia zi
b) 5*e/10=10
5*e=100, e=100/5=20exercitii in total
