1.Which of the following polynomials has/have unlike terms?
I.5a+5ab
II.4a^2-6a^2
III.6a^2+6a
A.I only
B.II only
C.I and III only
D.I,II and III
2.Simplify 5x^2-2x+2x^2.
3.(2a^2b^2)(-2ab)=
A.-4a^3b^3
B.-4ab
C.-ab
D.2a^2b^2-2ab
4.Which of the following descriptions of polygons Must be correct?
A.Any rhombus must be a regular polygon.
B.Any isosceles triangle must be a regular polygon.
C.All interior angles of any regular polygon must be acute.
D.All sides of any regular polygon must be equal in length,
5.In the figure,the pyramid has a square base with a side length of 10cm.Its
height is 12cm.The volume of the pyramid is
A.400cm^3
B.480cm^3
C.1200cm^3
D.3600cm^3
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中二三數學問題求幫忙(10點)
2012-12-26 8:00 pm
回答 (2)
2012-12-26 8:20 pm
✔ 最佳答案
1 A. Since it contains two variables a and b2 5x^2-2x+2x^2.= 7x^2 - 2x= x(7x - 2)3 (2a^2b^2)(-2ab)= -4a^3b^3 (A)4 D.All sides of any regular polygon must be equal in length5 Volume= (1/3) * base * height= (1/3) * 100 * 12= 400 cm^3 (A)
2012-12-27 10:40 am
1. C. I and III only
Only I and III contain unlike terms.
In III, a^2 and a are unlike terms. In a^2, a is raised to the power 2, while a is raised to the power 1.
Like terms are terms that contain the same variables raised to the same power. Only the coefficients of like terms are different
2. 5x^2 -2x + 2x^2. = 7x^2 - 2x
3. A . 4a^3b^3
4 D. All sides of any regular polygon must be equal in length
Regular polygon must have equal sides and equal angles.
A. Any rhombus must be a regular polygon. ~ wrong
Rhombus can have unequal angles.
B. Any isosceles triangle must be a regular polygon. ~ wrong
Isosceles triangle only has two equal sides; the third side has different length)
C. All interior angles of any regular polygon must be acute ~ wrong
Any regular polygon which is more than 4 sides can have interior angles greater than 90 deg.
5 A. 400 cm^3
Volume of pyramid = (1/3) * base area * height
= (1/3) * (10 cm * 10 cm) * 12 cm
= 400 cm^3
Note: * denotes multiply
Only I and III contain unlike terms.
In III, a^2 and a are unlike terms. In a^2, a is raised to the power 2, while a is raised to the power 1.
Like terms are terms that contain the same variables raised to the same power. Only the coefficients of like terms are different
2. 5x^2 -2x + 2x^2. = 7x^2 - 2x
3. A . 4a^3b^3
4 D. All sides of any regular polygon must be equal in length
Regular polygon must have equal sides and equal angles.
A. Any rhombus must be a regular polygon. ~ wrong
Rhombus can have unequal angles.
B. Any isosceles triangle must be a regular polygon. ~ wrong
Isosceles triangle only has two equal sides; the third side has different length)
C. All interior angles of any regular polygon must be acute ~ wrong
Any regular polygon which is more than 4 sides can have interior angles greater than 90 deg.
5 A. 400 cm^3
Volume of pyramid = (1/3) * base area * height
= (1/3) * (10 cm * 10 cm) * 12 cm
= 400 cm^3
Note: * denotes multiply
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