For example, x ^ 2 is the second power of X, how to simplify the latter algebraic expression? X ^ 2-3x + 1 = 0, find the value of 2x ^ 5-5x ^ 4-x ^ 3 + x ^ 2-6x / x ^ 2 + 1,

For example, x ^ 2 is the second power of X, how to simplify the latter algebraic expression? X ^ 2-3x + 1 = 0, find the value of 2x ^ 5-5x ^ 4-x ^ 3 + x ^ 2-6x / x ^ 2 + 1,

2x^5-5x^4-x^3+x^2-6x/(x^2+1)
=2x^5-5x^4-x^3+x^2-6x/3x
=2x^5-5x^4-x^3+x^2-2
=2x^3(x^2-3x+1)+x^4-3x^3+x^2-2
=2x^3*0+x^2(x^2-3x+1)-2
=x^2*0-2
=-2.

-5x+4=3x-4 -2x=-5/6x+2 3x-4/1=-4/x+1 Divide 100 into two parts, so that the first number plus 3 is equal to the second number minus 3. What are the two numbers? Use the equation to solve

-5x+4=3x-4
-5x-3x=-4-4
-8x=-8
X=1
-2x=-5/6x+2
-10x=-6x+10
-4x=10
x=-5/2
3x-4/1=-4/x+1
12x-1=-x-1
11x=0
X=0
100=(50+3)+(50-3)=100

Solve equation 3 problem 1, 1 + x = 2x 2 of 3, 3x-5 = 6x3, 5x + 7 = 3x + 10

1 + x = 2x of 3 and multiply both sides by 3
3+3x=2x
3x-2x=-3
x=-3
3x－5=6x
6x-3x=-5
3x=-5
X = - 5 / 3
5x＋7=3x＋10
5x-3x=10-7
2x=3
X = 3 / 2

First, simplify and then evaluate, (3x + 2) (3x-2) - 5x (x-1) - (2x-1) 2, where x = − 1 3．

Original formula = 9x2-4 - (5x2-5x) - (4x2-4x + 1)
=9x2-4-5x2+5x-4x2+4x-1
=9x-5，
When x = 1
At 3:00,
The original formula = 9x − 5 = 9 × (− 1)
3)−5=-3-5=-8．

First simplify, then evaluate: 3x's Square - [5x - (X-2) + 2x's Square], where x = - 1 / 2 （1）6x－（2x－3） （2）a+（Aa－2b）－（－a－b） (3) (the square of a + the square of 2Ab + b) - (the square of a - the square of 2Ab + b) (4) X - (1-2x + X's Square) - 2 (square of x-1)

The square of 3x - [5x - (X-2) + the square of 2x], where x = - 1 / 2 = the square of x-4x-2 = 0 (1) 6x - (2x-3)) = 4x-3 = - 5 (2) a + (aa-2b) - (- a-b) = a + aa-2b - (- (a + b)) = a + aa-2b + A + B = 2a-b + AA (3) (the square of a + 2Ab + b) - (the square of a -... "

First simplify and then evaluate: (3x-y) * 2 - (2x + y) * 2-5x (X-Y), where x = 2, y = 1

（3x-y)*2-(2x+y)*2-5x（x-y)
＝6x-2y-4x-2y-5x^2+5xy
＝2x-4y-5x^2+5xy
When x = 2, y = 1
Original formula = 4-4-5 * 4 + 5 * 2 * 1
＝－10
I always think that the "*" in the students' questions should be the power mark "^". If it is, the answer is as follows:
（3x-y)^2-(2x+y)^2-5x（x-y)
＝9x^2-6xy+y^2-(4x^2+4xy+y^2)-5x^2+5xy
＝9x^2-6xy+y^2-4x^2－4xy－y^2－5x^2+5xy
＝－5xy
When x = 2, y = 1
The original formula = - 5 * 2 * 1
＝－10
Jiangsu Wu Yunchao answers for reference!

-3x squared + 5x-0.5x squared + X-1, where x = - 2 (simplify and then evaluate)

-3x squared + 5x-0.5x squared + X-1
=-3.5x²+6x-1
When x = - 2, the above formula is as follows:
-3.5*(-2)²+6*(-2)-1
=-3.5*4-12-1
=-14-12-1
=-27

First simplify and then evaluate: (5x + 3) (5x-3) - 7x (3x-1) - (2x-1) ^ 2 when x = - 1 / 11

(5x+3)(5x-3)-7x(3x-1)-（2x-1）^2
=25x² -9-21x²+7x-4x²+4x-1
=11x-10
=-1/11x11-10
=-1-10
=-11
If there is anything you don't understand, you can ask,

(3x + 2) (3x-2) - 5x (x-1) - (2x-1), x = one third

(3x + 2) (3x-2) - 5x (x-1) - (2x-1), x = one third
Remove brackets; 3x + 6x-2-5xx-1
Simplification: 9x-5xx-1
Algebraic expression; 9 * 1 / 3-5 * 1 / 3 * 1 / 3-1
Operation; 3-0.56-1
Results: 1.44

Solution equation: 1 / 4x-1 / 2 = 3 / 4 1 / 2x-7 = 9x-2 / 6 1 / 5x-1 / 2 (3-2x) = 1

1/4x-1/2=3/4
x-2=3
X=5
1/2x-7=9x-2/6
3x-42=9x-2
6x=-40
x=-20/3
1/5x-1/2(3-2x)=1
2x-5(3-2x)=10
2x-15+10x=10
12x=25
x=25/12