(2x + 10 square + 3 (2x + 10) + 2 = 0 (factorization)

(2x + 10 square + 3 (2x + 10) + 2 = 0 (factorization)

(2x+10)²+3(2x+10)+2=0
[(2x+10)+1][(2x+10)+2]=0
(2x+11)(2x+12)=0
x1=-5.5 x2=-6

How much is 18 times 5 of minus 9 and 19
Urgent ah, to arithmetic, remember, arithmetic!

It's 14 out of 13 and 19

How much is cos (- 1182 degrees and 13 minutes)?

Cos (- 360 * 3-102) degree 13 min = cos (- 102'13 ') = sin (12'13') - 0.21160910627

Mathematical straight line and equation (16 12:26:25)
The ray OA and ob are at 45 ° and 30 ° angles to the positive half axis of x-axis respectively. A straight line AB crosses OA and ob at a and B respectively through point P (1,0)
(1) When the midpoint of AB is p, the equation of line AB is obtained
(2) When the midpoint of AB is on the line y = 1 / 2x, the equation of the line AB is obtained

I understand that O is the coordinate origin
The straight line of OA is y = X
The straight line of ob is y = √ 3x / 3,
(1) Let the equation of line passing through point p be y = K (x-1)
By combining the above three equations, we can get a (- K / (1-k), Y1), B (K / (√ 3 / 3-K), Y2), because the midpoint of AB is p, so - K / (1-k) + K / (√ 3 / 3-K) = 2, (using the midpoint to calculate coordinates) we can get K
(2) : then the midpoint coordinate is d. according to (1), we can know that the ordinate and abscissa of the midpoint D in AB are 1 / 2 of the corresponding coordinate sum of a and B. then we can get the target by substituting the coordinates of D (x, y) into y = 1 / 2x. Please forgive me for the trouble in the process

How many scores meet the following conditions at the same time? (1) More than 16 and less than 15; (2) both numerator and denominator are prime numbers; (3) denominator is two digits. Please list all the scores that meet the conditions

Let the score be Mn, where m and N are prime numbers, and N is 2 digits. According to the meaning of the question, we can get: 15 > Mn > 16, then 6m > N, 5m < n, that is 6m > n > 5m. Because n is 2 digits, so 5m < 100, then M < 19, when m = 2, 12 > n > 10, so n = 11, when m = 3, 18 > n > 15, so n = 17, when m = 5, 30 > n > 25, so n = 29, when m = 7, 42 > n > 35, so n = 41 or 37, when m = 11, 66 When m = 13, 78 ＞ n ＞ 65, so n = 67, 71, 73, when m = 17, 102 ＞ n ＞ 85, so n = 89, 97, so there are 211317529737741115916113671371137317891797 scores that meet the three conditions at the same time. A: there are 12 scores that meet the following conditions at the same time

The common solution of the equation 2x-y = 7 and X + 2Y = - 4 is
Hurry!

2x-y=7(1)
x+2y=-4（2）
2 x + 4Y = - 8 (3) from (2)
（3）-（1）
4y-(-y)=-8-7
y=-3
Substituting y = - 3 into (1)
x=2
It can also be solved in such a way that X or Y is equal to one formula calculated by one formula and then substituted into another formula

The calculated value of sin68 ° sin67 ° - sin23 ° cos68 ° is______ ．

Sin68 ° sin67 ° - sin23 ° cos68 ° = sin68 ° cos23 ° - sin23 ° cos68 ° = sin (68 ° - 23 °) = sin45 ° = 22, so the answer is: 22

The sum of 4 / 7 of a number and 30% of the number is 12.2. Find the number (by equation)
Many of the answers are written as 14, all of which regard "a number" as "this number". I think if these two are the same number, the title should be "the sum of 4 / 7 of this number and 30% of this number is 12.2, find this number". I don't understand why 12.2 can be divided by the sum of these two numbers. Who can tell me?

4/7x+30%x=12.2
61/70x=12.2
x=14

Xiaohong read 25% of a book in 8 days, and prepared to finish the rest in 6 days. What percentage of the book does she read every day?

(1-25) △ 6, = 35 △ 6, = 110; a: an average of 110

If point a (x, 4-2x) is on the bisector of the first and third quadrants, then x = 0___ If point a is on the bisector of the second and fourth quadrants, then x = 0___ ．

When a (x, 4-2x) is on the bisector of the first and third quadrants, then x = 4-2x, the solution is: x = 43; when point a is on the bisector of the second and fourth quadrants, then x + (4-2x) = 0, the solution is: x = 4