giup mk nha , cac ban

bai 1: mot hop chat khi duoc tao boi 2 nguyen to C va H ,trong do cC chiem 82,76 phan tram ve KL. Phan tu khoi cua hop chat =58

a, Xac dinh so nguyen tu cua moi hop chat co trong 1 phan tu hop chat

bai2: mot hop chat khi phan tu co 85,7C ve KL , con lai la H . Phan tu khoi cua hop chat la 28 . tim so nguyen tu cua moi nguyen to co trong moi phan tu cua hop chat

Phan tich so A=1.2.3.4....59.60 ra thua so nguyen to thi so mu cua cac thua so nguyen to 2 va 7 la bao nhieu

Giup minh voi cac ban oi $$$$$

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

1 hop chat XY₂ thoa man

- tong hat proton trong hop chat la 32

-hieu so hat X va Y tong hop chat la 24

- X va Y deu co so proton bang so notron

Xac dinh ten 2 nguyen to X, Y tu do suy ra cong thuc hoa hoc va tinh phan tu khoi cua hop chat

giup minh voi cac ban oi!

Tim so tu nhien co hai chu so khac nhau . Biet rang: hai chu so cua so do deu la so nguyen to . Tich cua so do voi cac chu so cua no la so co 3 chu so giong nhau duoc tao thanh tu chu so hang don vi cua so do.

1) Mot so nguyen to chia cho 30 duoc so du la r.Tim r,biet r khong phai la so nguyen to.

2) Chung minh rang:

a/ So 17 khong viet duoc tong 3 hop so khong bang nhau.

b/Moi so le lon hon 17 deu viet duoc duoi dang 3 hop so khac nhau. 

khi phan tich  cac so :21345;14190;243135 ra thua so nguyen to thi khi nao :

a.co chua thua so nguyen to 5?

b. co chua thua so nguyen to 3 va 5?

c.co chua thua so nguyen to2;3 va 5?

ai tra loi duoc cau nay thi ket ban minh nhe 

Cho A=5+5^2+5^3+...+5^2016

a, A la hop so hay so nguyen to 

b,A co phai la so chinh phuong khong ?

giup minh giai voi nha cac  ban \(\)