tong sau la so nguyen to hay hop so :
a) 2 . 3 .5 + 9 . 31
b ) 5 . 6 . 7 + 9 .10 . 11
tong sau la so nguyen to hay hop so
a, 3.5.7.9.11+11.35
b,5.6.7.8+9.77
c,105 +11
Bai 1:tim so nguyen P biet P+2va P+4 deu la nguyen to
bai 2: tong 2^100×7×11+81^3 la nguen to hay hop so ( giai thich)
Bai 3: tim so nguyen to P de P +2,p+6,P+8 deu la cac so nguyen to
Nhanh nhanh giai giup nha moi nguoi toi sap bai kiem tra mot tiet may bai nay roi
Ban nao dung minh se tich
Bai 1Tim nguyen to a de 4a+11 la so nguyen to nho hon 30
Bai 2 cac so sau la so nguyen to hay so hop so:
a=1*3*5*7*....*13+20
b=147*247*347-13
Bai 1
vì (30-11):4=4.75 nen a <5
nguyên tố bé hơn 5 chỉ có 2 và 3 nên a =2;3
Vậy a ={2;3}
tong ,hieu sau la so nguyen to hay hop so
A=45+36+72+81
B=4.19-5.4
C=7+72+7+.....+75
TONG SAU LA SO NGUYEN TO HAY HOP SÒ
2.3.5.9+31
tong sau day la so nguyen to hay hop so: 3.5.7 + (2n+1).(2n+3).(2n+5) voi n la so tu nhien
tong hoac hieu sau day la so nguyen to hay hop to
bai 1015+11
a,so 102010+8 chia het cho 9 ko?vi sao
b,tong 2100.7.11+381.13.14 la so nguyen to hay hop so?(giai thich)
ai nhanh cho nghin like
xet xem cac tong hieu sau la nguyen to hay hop so
a. 5+5 2+5 3+5 4
b. 2007 2+2010 4
a 5+5 2+5 3+5 4=50 là hợp số vì nó chia hết cho 2
B 2007 2+2010 4 = 12054 là hơp số vì nó chia hết cho 2