1. notam lungimea traseului cu t
prima zi: [tex]\frac{1}{4} *t=\frac{t}{4} \\[/tex]
restul: [tex]t-\frac{t}{4} =\frac{3t}{4}[/tex]
a doua zi: [tex]\frac{1}{3} *\frac{3t}{4}+200 =\frac{t}{4}+200= \frac{t+800}{4}[/tex]
restul: [tex]t-\frac{t+800}{4} =\frac{3t+800}{4}[/tex]
a treia zi: [tex]\frac{13}{25}* \frac{3t+800}{4} =\frac{39t+10400}{100}[/tex]
a patra zi: 120km
[tex]t=\frac{t}{4} +\frac{t+800}{4}+\frac{39t+10400}{100} +120\\t=\frac{25t}{100} +\frac{25t+20000}{100} +\frac{39t+10400}{100} +\frac{12000}{100}\\t=\frac{25t+25t+20000+39t+10400+12000}{100} \\t=\frac{89t+43400}{100} \\100t=89t+43400\\2t=43400\\t=21700km[/tex]
b)prima zi: [tex]\frac{t}{4} =\frac{21700}{4} =5425km[/tex]
a doua zi: [tex]\frac{t+800}{4} =\frac{21700+800}{4} =\frac{22500}{4} =5625km[/tex]
a treia zi: [tex]\frac{39t+10400}{100} =\frac{39*21700+10400}{100} =8567km[/tex]
ex 2,3 sunt atasate mai sus
