Giả sử : 2ab + 1 = c2
3ab + 1 = d2
=> ab = d2-c2
=> ab = (d - c)(d + c)
Giả sử : 2ab + 1 = c2
3ab + 1 = d2
=> ab = d2-c2
=> ab = (d - c)(d + c)
tim so ab biet :
2ab +1 va 3ab +1 deu la so chinh phuong
Tim so ab biet :
2ab +1 va 3ab + 1 deu la so chinh phuong
tim so nguyen to ab co 2 chu so khac nhau sao cho ba cung la 1 so nguyen to va ab - ba la 1 so chinh phuong
a)so sanh E=2018^99-1/2018^100-1 va F=2018^98/2018^99-1
b)Tim so nguyen to ab (a>b>0),biet ab-ba la so chinh phuong
c)Cho abc la so tu nhien co 3 chu so .Tim gia tri lon nhat cua A={abc/a+b+c}+1918
tim so tn co 2 chu so biet hieu cac binh phuong cua so do va so viet boi 2 cs cua so do nhung theo hung nguoc lai la so chinh phuong
1.Tren nua mp bo chua tia Ox,ve cac tia Ox1,Ox2,Ox3,...,OxN sao cho:
xOx2=2xOx1,xOx3=3xOx1,.......,xOxN=NxOx1.tim so N nho nhat de trong cac tia da ve co mot tia la tia phan giac chung cua 2017 goc
2.CMR:neu p la so nguyen to lon hon 3 va 2p+1 cung la so nguyen to thi 4p+1 la hop so
3.So sanh: 63^15 va 34^18
4.tim cac so tu nhien n co hai chu so biet:2n+1 va 3n+1 deu la so chinh phuong
5.CMR: S=16^5+2^15 chia het cho 33
Tim y thuoc N: y+50 va y-23 deu la cac so chinh phuong
tim so tu nhien a sao cho a+593 va a-159 deu la so chinh phuong
TIM SO NGUYEN TO CO 3 CHU SO BIET KHI VIET THEO THU TUNGUOC LAI NO LA 1 SO CHINH PHUONG