Question

Calculați sumele algebrice:
S1=9/2-13/2-5/2+2=
S2=1,76-2,04+1,12+0,92-3,23=
S3=-113/20+12,25-71/10+5,65-17,9=

Answer 1

S1=9/2-13/2-5/2+2
S1=(9-13-5)/2+2/1, amplifici 2/1 cu 2
S1=(-4-5)/2+4/2
S1=(-9+4)/2
S1=(-5)/2
S1=-2,5

S2=1,76-2,04+1,12+0,92-3,23
S2=-0,28+2,04-3,23
S2=1,76-3,23
S2=-1,47

S3=-113/20+12,25-71/10+5,65-17,9
S3=-113/20+1225/100-7110/10+565/100-179/10
Aplifici -113/20 cu 5, 7110/10 cu 10 si 179/10 cu 10
S3= -565/100+1225/100-71100/100 +565/100-1790/100
S3=(-565+1225-71100+565-1790)/100, -565 se simplifica cu +565
S3=(1125-71100-1790)/100
S3=(-69975-1790)/100
S3=(-71765)/100
S3=-717,65