Question

Afla nr.necunoscut:
a)324+3*{386+[48+2*(5*a-16*5)]}=1866
b)6+4*{2+3*[8-2*(a-3*5)]}=86

Answer 1

a) 324+3x{386+[48+2x(5a-80)]}=1866
324+3*y=1866
3y=1866-324=1542
y=1542:3=514
386+[48+2x(5a-80)]=514
386+b=514
b=514-386=128
48+2x(5a-80)=128
48+2xc=128
48+2c=128
2c=128-48=80
c=80:2
c=40
5a-80=40
5a=80+40=120
a=120:5=24
P.S.-x=inmultire

Answer 2

a)324+3x{386+[48+2x(5xa-16x5)]}=1866
3x{386+[48+2x(5xa-16x5)]}=1866-324
3x{386+[48+2x(5xa-16x5)]}=1542
386+[48+2x(5xa-80)]=1542:3
386+[48+2x(5xa-80)]=514
48+2x(5xa-80)=514-386
48+2x(5xa-80)=128
2x(5xa-80)=128-48
2x(5xa-80)=80
(5xa-80)=80:2
5xa-80=40
5xa=40+80
5xa=120
a=120:5
a=24

b)6+4x{2+3x[8-2x(a-15)]}=86
4x{2+3x[8-2x(a-15)]}=86-6
4x{2+3x[8-2x(a-15)]}=80
2+3x[8-2x(a-15)]=80:4
2+3x[8-2x(a-15)]=20
3x[8-2x(a-15)]=20-2
3x[8-2x(a-15)]=18
8-2x(a-15)=18:3
8-2x(a-15)=6
2x(a-15)=8-6
2x(a-15)=2
a-15=2:2
a-15=1
a=1+15
a=16