The equation has three properties:
Property 1: Two sides of the equation are added (or subtracted) with equal numbers or expressions, and the two sides are still equal.
If a=b
Then there is a+c = b+C.
Property 2: Two sides of an equation are multiplied (or divided) by an equal non-zero number or formula at the same time, and the two sides are still equal.
If a=b
Then there is a c = b c
Or a \c = b \c(a, b≠0 or a=b, c≠0).
Property 3: Both sides of the equation are multiplied (or squared) at the same time, and both sides are still equal.
If a=b
Then there is a c = b C
Or (radical c a) = (radical c b)
Equivalent substitution:
Substitute one quantity (or part of a quantity) for another quantity (or part of another quantity) equal to it. . "Equivalent substitution" means that a quantity is replaced by an equivalent quantity, which is a basic thinking method in mathematics and the basis of algebraic thinking method. The idea of equivalent substitution is embodied in the nature of equality, that is, the transitivity of equality: if a = b and b = c, then A = C. This mathematical thinking method is not only widely used, but also the basis for further learning mathematics.
For example:
Get ∠ A+∠ C = ∠A=∠B+∠ C from ∠ A = ∠ B.
This is the nature of the equation used.
And from ∠ A = ∠ B, ∠ B = ∠ C, ∠ A = ∠ C is obtained.
This is equivalent replacement.
Jiangsu Wu Yunchao wishes you academic progress.