1 cong 2 tru 3 tru 4 cong 5 cong 6 tru ........tru 303 tru305
1 cong 2 tru 3 tru 4 cong 5 cong 6 tru ........tru 303 tru305
1 cong 2 cong 4 tru 3 tru 4 bang bao nhieu
tim z,y,z thoa
can x cong can tat ca y tru 1 cong can tat ca z tru 2 bang 1 phan 2 ( x cong y cong z)
tim GTN cua B bang 1 phan x tru can x cong 1
tim x thuoc z de can x cong 1 phan can 3 tru 3 la so nguyen
tinh tong T bang 1 phan can 1 cong can 2 cong 1 phan can 2 cong can 3 cong ... cong den 1 phan can 99 cong can 100
so bi tru bang so tru cong voi 37,73.so bi tru cong voi so tru bang 60,27.tim so bi tru ,so tru.
Goi so bi tru la a va so tru la b
Ta co :
a=b+37,73
a-b=37,73
a+b=60,27
Ap dung tong hieu , ta duoc :
a=(60,27+37,73):2=49
b=49-37,73 = 11,27
Vay so bi tru la 49 va so tru la 11,27
**** nhe
11.27 va 49 la dung to thu roi
tinh ; a 15,3 chia [1 cong 0.25 nhan 16 ] b 40,28 tru 22,5 chia 12.5 cong 1.7 c 18 tru 10,5 chia 3 cong 5
a)15,3:(1+0.25x16)
=15,3:(1,25x16)
=15,3:20
=0,765
b)40,28-22,5:12,5+1,7
=40,28-1.8+1,7
=38,48+1,7
=40,18
c)18-10,5:3+5
=18-3,5+5
=14,5+5
=15
học tốt nha!
tinh nhanh [200 tru 58] nhan 58 cong [100cong 42] nhan 42
50 tru 51 cong 40 tru 41 cong 30 tru 31 cong 60
28 cong 62 nhan a nhan [ a nhan 1 tru a chia 1] cong 28 nhan 8 cong
jup mk nha mk dg voi tat ca deu la tinh nhanh nha ai jup hay ai ko jup thi cung kp voi mk nha
a) ( 200 - 58 ) x 58 + ( 100 + 42 ) x 42
= 142 x 58 + 142 x 42
= 142 x ( 58 + 42 )
= 142 x 100
= 14200
b) 50 - 51 + 40 - 41 + 30 - 31 + 60
= ( 50 + 40 + 30 ) - ( 51 + 41 + 31 ) + 60
= 120 - 123 + 60
= -3 + 60
= 57
caau b ko chắc
c) 28 + 62 x a x ( a x1 trừ a : 1 ) cộng 28 x 8 cộng
= 28 + 62a x 0 + 28 x 8
= 28 x 1 + 0 + 28 x 8
= 28 x ( 1 + 8 )
= 28 x 9
= 252
:V cái đề. Mk viết lại tí nha !
(200-58).58+(100+42).42
50-51+40-41+30-31+60
28+62.a.(a.1-a:1)+28.8+
bai 1 ;chung minh rang abcd chia het 99 thi ab cong cd chia het 99 va nguoc lai
bai 2;a.8 mu 10 tru 8 mu 9 tru 8 mu 8 chia het 55
b.7mu 6 cong 7 mu 5 tru 7 mu 4 chia het 11
d.10 mu 9 cong10 mu 8 cong 10 mu 7 chia het 555
c.81mu 7 cong 27 mu 9 tru 9 mu 13 chia het 45
Bài 1:
Ta có: abcd=100ab+cd=99ab+(ab+cd)
Vì 99 chia hết cho 99 =)ab chia hết cho 99=>(ab+cd) chia hết cho 99
Hay abcd chia hết cho 99;(ab+cd) chia hết cho 99
Vậy nếu abcd chia hết cho 99 thì (ab+cd) chia hết cho 99 và ngược lại
TINH BANG CACH THUAN TIEN NHA 3GIO 15PHUT nhan 7 cong 4,2 gio cong 3,25 gio nhan3 tru 2gio 12phut;b 1gio48 phut nhan 4 cong 216 phut nhan3 tru 1,5gio nhan 5
3 mu 3 nhan 9 tru 3 mu 4 nhan 3 cong 5 mu 8 nhan 5 mu 0 tru 5 mu 12 chia 25 mu 2
= 3^6 - 4 x 3 + 5^8 x 5^0 : 25^2
= 729 - 12 + 5^8 x 5^0 : 5^4
= 729 - 12 + 5^4
= 729 - 12 + 625
= 717 + 625
= 1342
\(3^3.9-3^4+5^8.5^0-5^{12}:25^2\)
\(=27.9-81+3905625.1-244140625:625\)
\(=-1235961951^{13}\)