a)463 + 318 + 137 + 22
= 463 + 137 + 318 +22
= 600 + 340
= 940
b) \(20+21+22+...+30\)
\(=\left(20+30\right)+\left(21+29\right)+\left(22+28\right)+\left(23+27\right)+\left(24+26\right)+25\)
\(=50+50+50+50+50+25\)
\(=250+25\)
\(=275\)
\(a.463+318+137+22.\)
\(=\left(463+137\right)+\left(318+22\right)\)
\(=600+340\)
\(=940\)
\(b.20+21+22+...+29+30\)
\(=\left(20+30\right)\times11:2\)
\(=50\times11:2\)
\(=550:2\)
\(=275\)
a. 463+318+137+22=(463+137)+(318+22)=600+340=940
b. Số số hạng:(30 - 20) : 1 +1=11
Tổng: (30+20) . 11 : 2 = 275
a)463+318+137+22
=(463+137)+(318+22)
=600+340
=940
b)20+21+22+...+29+30
=20+30
=50
a . 463 + 318 + 137 + 22 = 940
b. 20+21+22+...+29+30=30 x 11 / 2 = 330/2 = 165
a) 463+318+137+22
= (463+137)+ (318+22)
= 600 + 340
= 940
b) 20+21+22+...+29+30
so so hang: (30-20) :1 +1= 11 (so)
tong: (30+20)*11/2= 275.
k min nha! chuc ban luon hoc tot!