1 1. 1 line segment related to triangle
Information technology uses drawing to find rules
1 1.2 Angle related to triangle
Why do you have to prove it when reading and thinking?
1 1.3 sum of polygons and their internal angles
Mathematical activities
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Review questions 1 1
Chapter 12 congruent triangles
12. 1 congruent triangles
12.2 Determination of Triangular Congruence
Using information technology to explore the conditions of triangle congruence
Properties of 12.3 bisector
Mathematical activities
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Review questions 12
Chapter 13 Axisymmetric
13. 1 axisymmetric
13.2 draw an axisymmetric figure
Application of information technology in axisymmetric pattern design
13.3 isosceles triangle
The unequal relationship between the sides and angles of a triangle is explored experimentally.
13.4 the shortest path problem of project learning
Mathematical activities
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Review questions 13
Chapter 14 multiplication and factorization of algebraic expressions
14. 1 multiplication of algebraic expressions
14.2 multiplication formula
Reading and Thinking about Yang Hui Triangle
14.3 factorization
Mathematical activities
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Review questions 14
Chapter 15 Scores
15. 1 score
15.2 decimal operation
Reading and thinking. The water in the container can be emptied.
15.3 fractional equation
Mathematical activities
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Review questions 15
Index of some Chinese and English words
The formula of algebraic expression knowledge summary in eighth grade mathematics is the product of numbers or letters, which is called monomial. A single number or letter is also a monomial.
The numerical factor in a single item is called the coefficient of the item.
In a monomial, the sum of the exponents of all the letters is called the degree of the monomial.
The sum of several monomials is called polynomial. Each monomial is called a polynomial term ($ TERM) and those without letters are called constant terms.
The degree of the term with the highest degree in a polynomial is the degree of this polynomial.
Monomial and polynomial are collectively called algebraic expressions.
Items with the same letter and the same letter index are called similar items.
Merging similar terms in polynomials into one term, that is, adding their coefficients as new coefficients, while the letter part remains unchanged, is called merging similar terms.
The addition and subtraction of several algebraic expressions is usually to enclose each algebraic expression in brackets and then connect them with addition and subtraction signs; Then remove the brackets and merge similar projects.
Same radix power multiplication, constant radix, exponential addition.
Power, constant radix, exponential multiplication
The power of the product is equal to multiplying each factor of the product by the power, and then multiplying it by the power.
Multiply a monomial by a monomial, and multiply them by their coefficients and the same letters respectively. For letters contained only in the monomial, they are used as a factor of the product together with its index.
Multiplying a polynomial by a monomial is to multiply each term of a polynomial by a monomial, and then add the products.
Multiply polynomials by multiplying each term of one polynomial by each term of another polynomial, and then add the products.
(x+p)(x+q)=x^2+(p+q)x+pq
Square difference formula: (a+b) (a-b) = a 2-b 2.
Complete square formula: (a+b) 2 = A2+2ab+B2 (a-b) 2 = A2-2ab+B2.
(a+b+c)^2=a^2+2a(b+c)+(b+c)^2
Same base powers divides, the base remains the same, and the exponent is subtracted.