А)) -3ц 1/2+ 2,3= -(2•3+1)/2+ 2ц 3/10= -7/2+ (10•2+3)/10= -7/2+ 15/10= -7/2+ 3/2= (-7+3)/2= -4/2= -2. ______ сократили 15/10 делим на 5, 15:5=3; 10:5=2; дробь новая 3/2=15/10.
б)) 2 целых 1/3 - 4,1 = (4•2+1)/3 -4 1/10= 9/3- (4•10+1)/10= 9/3- 41/10= (9•10)/(3•10)- (41•3)/(10•3)= 90/30-123/30= -33/30= -1ц 3/30= -1ц 1/10.
в)) 2 целых 3/4 * (-1,6) = (4•2+3)/4• (-1ц 6/10)= 11/4• (-(10•1+6)/10)= 11/4• (-16/10)= 11/1• (-4/10)= -44/10= -4ц 4/10= -4ц 2/5.
г)) -6,25 : 1 целая 1 /4= -6ц 25/100: (4•1+1)/4= -6ц 1/4: 5/4= -(4•6+1)/4• 4/5= -25/4• 4/5= -5/1• 1/1= -5.