Complement+Complement = sum can be used to derive addend = and-another addend.

Negative-negative = difference can be deduced as negative = negative+difference and negative = negative-difference.

Multiplier x Multiplier = Product can be obtained from Multiplier = Product ÷ another multiplier.

Dividend = Divider = Quotient Divider = Divider X Quotient can be derived.

Divider = Divider

If it is a dividend, divisor = quotient has a remainder.

So dividend = divisor x quotient+remainder

Divider = (Dividend-Remainder) ÷Quotient

Quotient = (dividend-remainder) divider

According to the above ideas, many equation problems can be solved.

The simplest calculation of x+2=4 is x=4-2=2.

If it is a five-level mathematical unary linear equation with multiple X sums, such as x+2x+x+5+3=20, first shift the unknown term containing x, where x is 1x, and calculate the shifted term by numbers. According to the above definition, addend+addend = and-another addend can be solved.

That is, 20-3-5= 12 calculates 4x= 12 and x= 12÷4=3.

If there are numbers and unknowns x on the left and right sides of the equation, change the sign when moving the term.

Such as 6x-9=3x.

The 3x on the right side of the left-right shift term becomes negative and becomes 6x-3x, while -9 moves to the right and becomes positive 9, that is, 3x=9 and x=3.

Parentheses should be solved according to addition and subtraction exchange method, multiplication and division exchange method, association law and distribution law.