\(a,=\left(891+109\right)+359\)
\(=1000+359\)
\(=1359\)
\(b=\left(\frac{19}{11}+\frac{3}{11}\right)+\frac{5}{13}\)
\(=2+\frac{5}{13}=\frac{31}{13}\)
\(c,=\frac{1}{5}\left(1+2+3+4+5+6+7+8+9\right)\)
\(=\frac{1}{5}\cdot45=9\)
a)=891+359+109
=(891+109)+35
=1000+359=1359
b)=19/11+5/13+3/11
=(19/11+3/11)+5/13
=2+5/13=31/13
c)=1/5+2/5+3/5+4/5+5/5+6/5+7/5+8/5+9/5
=(1/5+9/5)+(2/5+8/5)+(3/5+7/5)+(4/5+6/5)+5/5
=1+1+1+1+1=5
a, = 891 + 109 + 359
= 1000 + 359
= 1359
b = 11 19 + 11 3 + 13 5
= 2 + 13 5
= 13 31
c, = 5 1 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9
= 5 1 · 45
= 9
nhớ k cho mk nha
học tốt
a) = ( 891 + 109 ) + 359
= 1000 + 359
= 1359
Chúc bạn học giỏi ~~~
