19:43 Câu 1:
Given a rectangle ABCD with AB = 4cm. What is the length of the segment CD?
Answer: CD = cm Câu 2:
Evaluate expression
Answer: Câu 3:
Find
Answer:
How many axes of symmetry does a rectangle have?
Answer: Câu 5:
Find the negative value of
Answer: Câu 6:
Given a right triangle
Answer:
Câu 7:
Find the remainder in the division of
Answer: The remainder is Câu 8:
Find
Answer:
(Input the result in ascending order separated by ";") Câu 9:
Fill in the blank with >; < or =.
Fill in the blank with >; < or =.
10) Đặt biểu thức là A
\(A=x^2-x+1\)
\(\Leftrightarrow A=x^2-2.x.\left(\frac{1}{2}\right)+\left(\frac{1}{2}\right)^2-\frac{1}{2}^2+1\)
\(\Leftrightarrow A=\left(x-\frac{1}{2}\right)^2+\frac{3}{4}\)
\(\left(x-\frac{1}{2}\right)^2\ge0\Rightarrow\left(x-\frac{1}{2}\right)^2+\frac{3}{4}\ge\frac{3}{4}>0\)
Vậy điền dấu lớn hơn
9) Đặt biểu thức là B
\(B=-x^2+x-1\)
\(B=-\left(x^2-x+1\right)\)
\(B=-\left(x^2-2.x.\left(\frac{1}{2}\right)+\left(\frac{1}{2}\right)^2-\left(\frac{1}{2}\right)^2+1\right)\)
\(B=-\left(\left(x-\frac{1}{2}\right)^2+\frac{3}{4}\right)\)
\(B=-\left(x-\frac{1}{2}\right)^2-\frac{3}{4}\)
\(\left(x-\frac{1}{2}\right)^2\ge0\Rightarrow-\left(x-\frac{1}{2}\right)^2\le0\Rightarrow-\left(x-\frac{1}{2}\right)^2-\frac{3}{4}\le-\frac{3}{4}< 0\)Vậy điền dấu bé
1)4
2)200
3)10
4)2
5)-4
6)90
7)0
8)1
9)<
10)>
Chúc bạn học tốt
1) Hình chữ nhật có tính chất: Các cặp cạnh đối bằng nhau=> AB=CD mà AB=3cm=>CD=3cm
2) \(\frac{20x^5y^4}{10x^4y^2}=2xy^2\)
Thay x=25;y=2 ta có: 2xy2=2.25.22=200
3) \(x^2-20x+100=0\)
\(\Leftrightarrow\left(x-10\right)^2=0\)
\(\Rightarrow x=10\)