a)4,25+3,15+3,75+5,85=(4,25+3,75)+(3,15+5,85)=8+9=17.
b)(3/5+4/7)+2/5=(3/5+2/5)+4/7=1+4/7=11/7.
c)6,24+5,36+3,76=(6,24+3,76)+5,36=10+5,36=15,36.
d)(19/15+3/5)+11/15=(19/15+11/15)+3/5=2+3/5=13/5.
ủng hộ nha có j kb vs mk
Tính bằng cách thuận tiện nhất:
a ) 4,25 + 3,15 + 3,75 + 5,85
= ( 4,25 + 3,75 ) + ( 3,15 + 5, 85 )
= 8 + 9
= 17
tks giúp mk vs ạ!
a) 4,25 + 3,15 + 3,75 + 5,85 = ( 4,25 + 3,75 ) + ( 3,15 + 5,85 ) = 8 + 9 = 17
b) (3/5 + 4/7) + 2/5 = (3/5 + 2/5) + 4/7 = 1 + 4/7 = 7/7 + 4/7 = 11/7
c) 6,24 + 5,36 + 3,76 = (6,24 + 3,76) + 5,36 = 10 + 5,36 = 15,36
d) (19/15 + 3/5) + 11/15 = (19/15 + 11/15) + 3/5 = 2 + 3/5 = 10/5 + 3/5 = 13/5