Using the matching method, we make 6x? - 7x + 1 = O 5x? - 18 = 9x 4x? - 3x = 52 5x? = 4-2x

Using the matching method, we make 6x? - 7x + 1 = O 5x? - 18 = 9x 4x? - 3x = 52 5x? = 4-2x

6X? - 7x + 1 = 06 (x? - 7 / 6x + 49 / 144) - 6 * 49 / 144 + 1 = 06 (X-7 / 12) 2 = 150 / 144 (X-7 / 12) 2 = 25 / 144x-7 / 12 = ± 5 / 12x = 7 / 12 ± 5 / 12x = 1 or x = 1 / 65x? - 18 = 9x5x? - 9x-18 = 05 (x? - 9 / 5x + 81 / 100) - 5 * 81 / 100-18 = 05 (X-9

What is the number of? 1 x? + 2 x? + 3 x? + 4 x? + 5 x? + 6 x? + 7 x? + 8 x? + 9 x? + 10 x? = 1980

X(1+2+3+4+5+6+7+8+9+10+11)=1980,
X66=1980
It's 30

The sum equation s = │ 2x-1 │ + │ 3x-1 │ + │ 4x-1 │ + │ 5x-1 │ + │ 6x-1 │ + │ 7x-1 │ + 8x-1 │ + │ 9x-1 │ + │ 10x-1 │, when x takes a certain one When the value is in the range, s takes the same value. Find the value range of X and the value of s at this time

The only way to keep the value of s constant is that there are positive and negative values in the absolute value. After taking apart, all the X's are positive and negative, and only the constant 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 5454 / 2 = 27 is left, so │ 2x-1 │ + │ 3x-1 │ + │ 4x-1 │ + │ 5x-1 │ + │ 6x-1 │ 7x-1 │ all the six absolute values are less than or equal to 0

1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 We have to solve the equation

1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
120x=550
x=55/12=4.583

For the sum s = | 2x-1 | + | 3x-1 | + | 4x-1 | + | 5x-1 | + | 7x-1 | + | 8x-1 | + | 9x-1 | + | 10x-1 | When x takes a value in a certain range, s takes the same value. Find the value range of X and the value of s at this time

Using the geometric meaning, we can get that when x takes a value in the interval [1 / 8,1 / 7], s takes the same value, and the value is 3

First simplify, then evaluate: 5x2 + 4-3x2-5x-2x2-5 + 6x, where x = - 3

The original formula = (5-3-2) x2 + (- 5 + 6) x + (4-5)
=x-1，
When x = - 3, the original formula = - 3-1 = - 4

3x squared - (2x squared + 5x-1) - (3x + 1), where x = 10 urgent The square of 3x - (2x square + 5x-1) - (3x + 1), where x = 10 is specific The square of 3A B - [2A square B - (2abc-a square B) - 4A square C] - ABC, where a = - 2, B = - 3, C = 1

3x²-(2x²+5x-1)-(3x+1)
=3x²-2x²-5x+1-3x-1
=x²-8x
=10²-8×10
=20
3a²b-[2a²b-（2abc-a²b）-4a²c]-abc
=3a²b-2a²b+（2abc-a²b）+4a²c-abc
=a²b+2abc-a²b+4a²c-abc
=abc+4a²c
=6+16
=22

Find the value of the square of the polynomial 2x-5x + xsquare + 4x-3x-2, where x = negative half

2x squared-5x + xsquare + 4x-3x squared-2
=2x²+x²-3x²-5x+4x-2
=-x-2
=-(-1/2)-2
=1/2-2
=-3/2

Calculation: (3x + 2) (3x-2) - 5x (x-1) - (2x-1) 2

Original formula = 9x2-4-5x2 + 5x-4x2 + 4x-1
=9x-5．

5X-2（X-3）=15 X-3（2X+1）=6X-4（5-3X）

5X-2（X-3）=15
5X-2X+6=15
5X-2X=15-6
3X=9
X=9÷3
X=3
X-3（2X+1）=6X-4（5-3X）
X-6X-3=6X-20+12X
-5X-3=18X-20
18X+5X=20-3
23X=17
X=17÷23
X=17/23