Question

400+480÷4-[680: d+4×(20+12+18)]=286 și 30+5×{32÷8+5×[40+a×(160÷4-6×6) ]}=1850

Answer 1

400+480÷4-[680: d+4×(20+12+18)]=286
 400+120-(680:d+4x50)=286
520-(680:d+200)=286
680:d+200=520-286
680:d+200=234
680:d=234-200
680:d=34
d=680:34
d=20

30+5×{32÷8+5×[40+a×(160÷4-6×6) ]}=1850
30+5x{4+5x[40+ax(40-36)]}=1850
5x{4+5x[40+ax(40-36)]}=1850-30
5x{4+5x[40+ax(40-36)]}=1820
4+5x[40+ax(40-36)]=1820:5
4+5x[40+ax(40-36)]=364
5x(40+ax4)=364-4
40+ax4=360:5
40+ax4=72
ax4=72-40
ax4=32
a=32:4
a=8