Question

Ma puteti ajuta cu ex. Incercuite plz? Va dau coroana si 30 pct.

Answer 1

5)

a)[1/3+1/3÷(1-1/3)]÷3/2=
=1/3+1/3÷2/3×2/3=
=1/3+1/3×3/2×2/3=
=2/3

6)

a)1÷(1÷11/30-1,5) +2(la puterea-3)÷27/40=
=1÷(30/11-3/2)+1/2³ ×40/27=
=1÷27/22+1/8×40/27=
=22/27+5/27=
=1

7)

a)(-3/14+2²/7-5/2²×7)÷(-5/28)=
=(-3/14+4/7-5/4×7) ÷(-5/28)=
=(-3/14+4/7-5/28) ÷(-5/28)=
=5/28÷(-5/28)=
=-1

b) (2×1/3-1×4/21)÷(-3×11/21)=
=(2/3-4/21)÷(-11/7)=
=10/21÷(-11/7)=
=-10/21×7/11=
=-10/3×1/11=
=-10/33

10)îmi pare rău, pe asta nu știu cum să o fac:(

12)

a)[(-3²/28+1/7)+(2²/7-1/28)]×7=
=[(-9/28+1/7)+(4/7-1/28)] ×7=
=[(-5/28) +15/28] ×7=
=(-5/28+15/28)×7=
=5/14×7=
=5/2

b){1/7-[3/7+(5/28-5/84)]-1/21}÷7(la puterea -1)=
=(1/7-(3/7+5/42)-1/21)×7¹=
=(1/7-23/42-1/21)×7=
=-19/42×7=
=-19/6


succes!