cau 1: Cho A= \(\frac{100^{2014}+2}{3}-\frac{100^{2015}+17}{9}.\)tong cac cua so cua B=-9A

Cau 2: So sanh A=\(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+........+\frac{1}{100.101}\)voi 1 ta doc A....1

Cau 3 : Cho bon so a,b,c,d sao cho a+b+c+d khac 0 . Biet \(\frac{b+c+d}{a}=\frac{c+d+a}{b}=\frac{d+a+b}{c}=\frac{a+b+c}{d}=k\). Vay k=

Cau 4 : so cac so nguyen am x thoa man \(x^{2015}=\left(-2\right)^{2014}\)

Cau 5; tim x,y,z biet \(\frac{x}{y}=\frac{10}{9},\frac{y}{z}=\frac{3}{4}\)va x-y+z=78

Cau 6: tap hop cac so co ba chu so chia het cho 18 va tong cac chu so ti le voi 1;2;3 la

Cau 7: gia tri cua tong S=1.2+2.3+.....+49.50 la S=

Câu 13 Tập hợp tất cả các giá trị của x thỏa mãn \(x^3=-1\)laf :

A . ( 0;-1) B .(0) C.∅ D.(0;-1;1)

Câu 15: Cho ABC có MN //BC thì:

A.\(\frac{AM}{NC}\)=\(\frac{MB}{AN}\) B.\(\frac{AN}{MB}=\frac{AM}{NC}\) C.\(\frac{AM}{MB}=\frac{AM}{NC}\) D.\(\frac{MB}{MA}=\frac{NA}{NC}\)

Giai va bien luan cac phuong trinh sau:

1. \(\frac{a+b-x}{c}+\frac{a+c-x}{b}+\frac{b+c-x}{a}+\frac{4x}{a+b+c}=1\)

(an x) voi dk; a,b,b khac 0 va a+b+c khac 0

2.\(\frac{x-a}{bc}+\frac{x-b}{ac}+\frac{x-c}{ab}=2\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)\)

(an x) voi dk: a,b,c khac 0

3, \(\frac{mx+3}{6}+\frac{m^2-1}{2}=\frac{x+5}{10}+\frac{2}{5}\left(x+m^2+1\right)\)

(an x)

Cau 1; cho\(\frac{x}{2}=\frac{y}{5}\)vaxy=90. So cap (x;y) thoa man la

Cau 2 : Cho a+d=b+c va \(a^2+d^2=b^2+c^2\)(b,d khac 0).Khi do 4 so lap thanh ti le thuc nao

Cau 3 :GTLN cua phan so \(\frac{7n-8}{2n-3}\)

Cau 4: Cho A=\(\frac{12}{x-15}\)   dieu kien de 0<A<1 va A>1

Cau 5 ; tim x biet /-x-5//x=5=10

Cau 6: tap hop cac so nguyen cua x thoa man (3x^2-51)^2014=(-24)^2014

Cau 7: tap hop cac so thoa man /x-y/+/y+9/25/=0