Question

4 si 5 pls
Dau coroana

Answer 1

4. x + 5% din x = 315
x+ 5x/100 = 315
Amplificam x cu 100
(100x+5x)/100=315
105x=315 * 100
105x-31500
x=31500/105
x=300

5.x-15%din x= 612
x-15x/100=612
Amplificam x cu 100
(100x-15x)/100=612
85x=612*100
85x=61200
x=61200/85
x=720