1.
42:8 =5,25 lei/kg
11×5,25=57,75 lei
2.a=bani andrei
2a= bani ioana
2a-30=a+15
a=45 lei are andrei
2a=45×2=90 lei are ioana
3.
x= suma initiala
x/3=ziua 1
25%x=x/4
x-x/3-15=x/4
12x-4x-180=3x
5x=180
x=36 lei suma initiala
4.
a=pret stilou
b=pret carte
3a+4b=120 b=(120-3a)/4
7a+3b=185
7a+3×(120-3a)/4=185
28a+360-9a=740
19a=380
a=380:19=20 lei stiloul
b=(120-3×20)/4=(120-60)/4=60/4=15 lei cartea
