Cau 1:
a, trong cac bo 3 sau day, bo 3 so nao la bo 3 so doi mot so nguyen to cung nhau
A, 3;5;20
B, 2;7;31
C,4;9;117
D. 4;11;121
b, neu a thuoc UCLN ( 4,a ) va a < 4 thi
A.a=4
B. a=1
C.a=2
D. a chia het cho 4
Cau 2:thuc hien cac phep tinh
[5*/-55/-(125-5*/-49/)]+5*21
Cau 3:tim so nguyen x biet
a,7x-x=5^21:5^19+3*2^2-7^0
b,3^2(x+14)-5^2=5*2^2
c, 26-/x+9/=-13
Loga
Sinh Học lớp 12
