А) (3/4+1/6)×3+(5/6-1/2)÷2/9; б) (1 1/5+2 3/10)÷1/2+(6 3/4-2 2/3)÷1 1/6

(3/4+1/6)×3+(5/6-1/2)÷2/9=((2*3+3*1)/12)3+((6*5-2*1)/12)*9/2=(9/12)*3+(28/12)*9/2=9/4+14*3/4=9/4+42/4=51/4=12,75 б) (1 1/5+2 3/10)÷1/2+(6 3/4-2 2/3)÷1 1/6=(6/5+23/10)*2+(27/4-8/3):7/6=((6*2+23)/10)*2+(27*3-8*4)12)*6/7=(35/10)*2+(49/12)*6/7=35/5+7/2=7+3,5=10,5

а) 1) 3/4 + 1/6= 3*3/3*4 + 2*1/2*6= 9/12 + 2/12= 11/12 2) 11/12 * 3= 11/12 + 3/1= 11*3/12*1= 33/12= 11/4= 2 3/4 3) 5/6 - 1/2= 5*1/6*1 - 3*1/3*2= 5/6 - 3/6= 2/6= 1/3 4) 1/3 :2/9= 1/3 * 9/2= 1*9/3*2= 9/6= 3/2= 1 1/2 5) 2 3/4 - 1 1/2= 2*4+3/4 - 1*2+11/2= 11/4 - 3/2= 1*11/1*4 - 2*3/2*2= 11/4 - 6/4= 1 1/4 б) 1) 1 1/5 + 2 3/10= 5*1+1/5 + 10*2+3/10= 6/5 + 23/10= 2*6/2*5 + 1*23/1*10= 12/10 + 23/10= 35/10= 7/2= 3 1/2 2) 3 1/2 : 1/2= 3*2+1 * 2/1= 7/2 * 2/1= 7*2/2*1= 14/2= 7 3) 6 3/4 - 2 2/3= 6*4+3/4 - 2*3+2/3= 27/4 - 8/3= 3*27/3*4 - 4*8/4*3= 81/12 - 32/12= 81-32/12= 49/12= 4 1/12 4) 4 1/12 :1 1/6= 4*12+1/12 :1*6+1/6= 49/12 :7/6= 49/12 * 6/7= 294/84= 7/2= 3 1/2 5) 7 + 3 1/2= 7/1 + 3*2+1/2= 7/1 + 7/2=2*7/2*1 + 1*7/1*2= 14/2 + 7/2= 21/2= 10 1/2