Question

ex 1,2,3,4,5.Va rog urgent!!!Coroana!!!

Answer 1

1.stofa=a
postav=b

4a+3b=1250
2a+6b=1300
4a+3b+2a+6b=2550
6a+9b=2550
3(2a+3b)=2550/3=850
Daca 2a+3b=850 si 4a+3b=1250 rezulta 2a=1250-850=400
a=400/2=200 lei(metrul de stofa)
800+3b=1250
3b=1250-800=450
b=450/3=150 lei(metrul de postav)



2.stofa neagra=a
stofa verde=b

30a+40b=9750
a=3b
90b+40b=9750
130b=9750 rezulta b=9750/130=75 lei(stofa verde)
a=3x75=225 lei(stofa neagra)

3.dulapuri=a
mese=b
5b=2a
18a=7380 rezulta a=7380/18=410lei
5b=820 rezulta b=850/5=164 lei(o masa)
25x164=4100 lei(au costat mesele)


4.creioanele=a
pixuri=b
3a+4b=11
5a+2b=9
3a+4b+5a+2b=11+9=20
8a+6b=20
2(4a+3b)=20
4a+3b=10
3a+4b+3b+4a=21
7a+7b=21 rezulta a+b=21/7=3
3a+3b=9
3a+4b=11 rezulta ca b=11-9=2 lei (costa un pix)
3a+8=11
3a=11-8=3 rezulta a=1 leu(costa un creion)


5.pahare=a
farfurii=b
12a+10b=156
8b+10a=126
12a-10a+10b-8b=156-126=30
2a+2b=30
2(a+b)=30 rezulta a+b=30/2=15
6a+6b=6(a+b)=6x15=90 lei