In the second year of junior high school, the more the better, 50

Replace * to the 2nd power.

Common; （a+b）*=a*+2ab*+b*：（a-b）*=a*-2ab*+b*

Full square formula).

a* times a* = a*+*

Note that it does not have to be 2 power, the bases must be equal and the exponents are added) a* divided by a*=1

Same as above, but note that it stands to reason that the power of 0 of any number should be 0, but to be honest, it is 1, and the division is the exponential subtraction).

a+b+c)*=This is the multiplication of 2 such equations: a*+c*+b*+2ab+2ac+2bc

ab）*=a*b*

a-b）（a+b）=（a-b）*

Note that regardless of whether the plus sign is done or right, the result is minus).

It's tiring! How to play to the 2nd power.

;（a+b）*=a*+2ab*+b*：（a-b）*=a*-2ab*+b*

Full square formula).

a* times a* = a*+*

Note that it does not have to be 2 power, the bases must be equal and the exponents are added) a* divided by a*=1

Same as above, but note that it stands to reason that the power of 0 of any number should be 0, but to be honest, it is 1, and the division is the exponential subtraction).

a+b+c)*=This is the multiplication of 2 such equations: a*+c*+b*+2ab+2ac+2bc

ab）*=a*b*

a-b）（a+b）=（a-b）*

the formula for the operation of integers; We can replace it with numbers and people. For example, the area of a trapezoid: s = (top bottom, bottom bottom) height 2

As; 20 pieces of wood are stacked in a trapezoidal shape;

Use the formula s=(top bottom, bottom bottom) high 2

There are 2 at the bottom, 8 at the bottom, and 4 at the high. substitution formulas;

s=（2＋8）×4÷2

s=10×4÷2

s=20

Let's solve it in the simplest way:

Find out the integer they are close to first:

Then find them.

The integer of the broom approach:

30) to the power of 50.

Greater than (40) to the power of 40.

Greater than (50) to the power of 30.

33 to the 55th power.

Greater than 44 to the power of 44.

Greater than 55 to the power of 33.

Bonus points!

No matter what grade the formula is, it takes several steps to be able to use it:

One: Familiarize yourself with the formula.

Two: Find a few similar questions to do.

Three: Do more difficult questions.

Four: Memorize the formula.

itiseasy!

A to the 2nd power multiplied by a to the 3rd power is equal to a to the 5th power.

Multiply by the power of the base, and add the invariant exponent.

That's not 2 times 3 5, it's 2 and 3 5, i.e. 13 5

Solution: It can be known from the question.

Simplification of x(x-1)-(x -y)=x -x-x +y=-x+y= 2 , so x-y=2

And because, (x-y) x +y -2xy ; So, x +y = (x-y) +2xy =2 +2xy = 4+2xy

x²+y²／2-xy =（4+2xy）/2 -xy =2+xy-xy =2

The main ones are:

The perfect square formula A +2AB+B = (A+B).

The square difference formula a -b = (a+b)(a-b).

There aren't too many formulas for the first whole formula, you just need to practice more.