Question

1.h)1+(-3 supra 4)= i)-4 1  supra 5+(+4  1 supra 15 )=j)-7  1 supra 3 + 1     2 supra 9=  2.b) (-1 supra 3)+(-1 supra 6)+(+5 supra 8)+(-7 supra 12)=c)(+5 supra 18)+(-3 supra4)+(+2 supra 9)+(-5 supra 6)=d)(-4supra21)+(-6supra7)+(+5supra42)+(+9supra14)=

Answer 1

1. h)1+(-3/4)=1-3/4=4/4-3/4=1/4
i)1/5+4 1/15=1/5+(15·4+1)/15=1/5+61/15=3/15+61/15=64/15
j)-7 1/3+1 2/9=-(3·7+1)/3+(9·1+2)/9=11/3+11/9=33/9+11/9=44/9

2.b)-1/3+(-1/6)+5/8+(-7/12)=-4/12-2/12-7/12=-13/12
c)5/18+(-3/4)+2/9+(-5/6)=10/36-27/36+8/36-30/36=-39/36=-13/12
d)-(4/21)+(-6/7)+5/42+9/14=(-8/42)-36/42+5/42+27/42=-12/42=-2/7

/ inseamna supra
am amplificat fractiile sa le aduc la numitorul comun si am adunat si scazut