Tinh gia yri cua bieu thuc sau bqbg cach hop ly
0,2*517*9,7*483*2
Giup minh giai voi nhe
bai 3 : cho bieu thuc : a = 500 + x va b = x - 500 , voi x = 8075
a, tinh gia tri cua a va b
b , tinh gia tri cua a + b
giai theo cach lop 4 nhe , nhanh len
a = 500 + x = 500 + 8075 = 8575
b = x - 500 = 8075 - 500 = 7575
tinh gia tri cua bieu thuc sau bang cach hop ly 7
=
tinh gia tri bieu thuc sau bang cach hop li:
B=1,3-3,2+5,1-7=8,9-10,8+ .... + 35,5 -37,4+39,3-41,2+43,1
minh tim ra cach lam rui nhung cac ban lam ho minh cach ngan gon nhat nhe
thanh nhieu
cho bieu thuc:
A=(6-2/3+1/2)-(5+5/3-3/2)-(3-7/3+5/2)
hay tinh gia tri cua A theo hai cach
cach 1:truoc het tinh gia tri tung bieu thuc trong ngoac
cach 2:bo dau ngoac roi nhom cac so hang thich hop
C1: \(A=\left(\frac{36}{6}-\frac{4}{6}+\frac{3}{6}\right)-\left(\frac{150}{30}+\frac{50}{30}-\frac{45}{30}\right)-\left(\frac{18}{6}-\frac{14}{6}+\frac{15}{6}\right)\)
\(=\frac{35}{6}-\frac{155}{30}-\frac{19}{6}=\frac{35}{6}-\frac{31}{6}-\frac{19}{6}=-\frac{15}{6}=-2\frac{1}{2}\)
C2: \(6-\frac{2}{3}+\frac{1}{2}-5-\frac{5}{3}+\frac{3}{2}-3+\frac{7}{3}-\frac{5}{2}\)
\(=\left(6-5-3\right)-\left(\frac{2}{3}+\frac{5}{3}-\frac{7}{3}\right)+\left(\frac{1}{2}+\frac{3}{2}-\frac{5}{2}\right)\)
\(=-2-0-\frac{1}{2}=-2\frac{1}{2}\)
Tinh gia tri cua cac bieu thuc sau bang cach hop li
a) 125 : (-61) . (-23) . (-1) 2n
b) 136 . (-47) + 36 . 47
cho hinh vuong co do dai canh la a . hay viet bieu thuc tinh chu viP va bieu thuc tinh dien tich S cua hinh vuong theo a
ap dung : tinh gia tri cua bieu thuc P va S voi a = 7 cm ; a = 10cm
rui do giai di
tinh gia tri bieu thuc sau bang cach hop li nhat
3,265+4,572+2,735+1,128
3,265 + 4,572 + 2,735 + 1,128
= (3,265 + 2,735) + (4,572 + 1,128)
= 6 + 5,7
= 11,7
3,265+4,572+2,735+1,128
=(3,265+2,735)+(4,572+1,128)
= 6 + 6
= 12
tinh gia tri bieu thuc sau bang cach hop ly
1-6+11-16+21+...+91-96+101
1-6+11-16+21-...+91-96+101 =(1-6)+(11-16)+(21-26)+....+(91-96)+101 =(-5)+(-5)+.....+(-5)+101 (có 10 số (-5) ) =(-5).10+101 =-50+101 =51
tinh gia tri bieu thuc theo cach hop li neu co the )