Question

Calculati:
a) 2,6xy - 2,(3)xy + 1,(6)xy + (2,3xy - 0,9xy)
b) 2x/3 + 3x/5 - 0,3 + 1,(6)x - x
c) 0,5a + 2 intregi si 2/3 a - [0,(3)x - 2/3 x]
d) 13/5 x^2 - 11/6 x^2 + 1 intreg si 3/10 x^2 - 1/2 x^2 + 1,(3) x^2

Answer 1

a) 2,6xy - 2,(3)xy + 1,(6)xy + (2,3xy - 0,9xy)=
2,(3)=(23-2)/9=21/9=7/3
1,(6)=(16-1)/9-15/9=5/3
=2,6xy - 7xy/3 + 5/3xy + 1,4xy=
=4xy - 2xy/3=
=(12xy-2xy)/3=
=10xy/3


b) 2x/3 + 3x/5 - 0,3x + 1,(6)x - x=
=2x/3 + 3x/5 - 3x/10 + 5x/3 - x=
=(20x+18x-9x+50x-30x)/30=
=49x/30

c) 0,5a + 2 intregi si 2/3 a - [0,(3)x - 2/3 x]=
0,(3)=3/9=1/3
=5a/10 + 8a/3 - (x/3 - 2/3 x)=
=a/2 + 8a/3 +x/3=
=(3a+16a)/6+x/3=
=19a/6+x/3=
=(19a+2x)/6

d) 13/5 x² - 11/6 x²+ 1 intreg si 3/10 x² - 1/2 x² + 1,(3) x² =
1,(3)=(13-1)/9=12/9=4/3
=13x²/5 - 11x²/6+  13x²/10 - x²/2 + 4x²/3 =
=(78x² - 55x²+  39x² -15x² + 40x²)/30 =
=87x²/30 =29x²/10