Question

va rog ajutatima la exercitiile astea:
1) 5x-2=4x-1
2) f(x)=-3x+9
3) Dupa o ieftinire cu 12%un obiect costa 880.Pretul initial este.....
4)Ecuatia: I8-2xI=10

Answer 1

1.5x-4x=2-1
   x=1

3.880 lei ____________ 88%
    x   _______________ 100%
x=880·100/88=1000lei pretul initial

4.2x-8=10
   2x=18
    x=9

La ex.2 nu stiu ce ti se cere...

Answer 2

1) 5x-2=4x-1
5x-4x=2-1
x=1
2) f(x)=-3x+9
f(1)=-3+9=6
f(2)= -6+9=3
f(3)=-9+9=0
f(4)=-12+9= - 3

3
x.................100%
880 .......100-12=88%
x=880*100:88=1000 lei

4
|8-2x|=10
|8-2x| ≥0
2x-8=10
2x=18
x=9