(1) 2x-5x = 9 solve equation (2) 11y-3y-9y = - 6 (3) 2 / 2 X-2 / 2 3x = 5

(1) 2x-5x = 9 solve equation (2) 11y-3y-9y = - 6 (3) 2 / 2 X-2 / 2 3x = 5

（1）2x－5x＝9
-3x=9
x=-3
（2）11y－3y－9Y＝﹣6
-y=-6
Y=6
(3) 2 / X - 2 / 3x = 5
-x=5
x=-5
2x-5x=9 11y-3y-9y=-6 x/2-3x/2=5
-3x=9 - y=-6 -2x/2=5
x=-3 y=6 x=-5
2x-5x=9
-3x=9
x=-3
11y-3y-9y=-6
- y=-6
Y=6
x/2-3x/2=5
-2x/2=5
x=-5
Prime numbers in 19.29.39.49.59.69.79.89.99
It's going to count
19, 29, 59, 79 and 89
Prime 19, 29, 59, 79, 89
Total 39, 69, 99
19 29 59 79 89 are prime numbers
The rest is the sum
Prime number: 19 29 59 79 89
Total: 39 49 69 99
If - 4 ≤ a ≤ 3, then the probability of passing through point a (a, a) as two tangents of circle x ^ 2 + y ^ 2-2ax + A ^ 2 + 2a-3 = 0 is 0
A 3/7
B 1/7
C 4/7
Come down and have a look!
It is known that X and y are rational numbers. Now a new operation ⁃ is provided, which satisfies x ⁃ y = XY + 1 (1) to find the value of 2 ⁃ 4 (2) to find the value of (1 ⁃ 4) ⁃ 2 (3)
Explore the relationship between a (B + C) and a (B + a) C, and express it with equation
（1）=-7
（2）=-9
（3）=a※（b+c)+1=a※b+a※c
Simplification and calculation (x ^ 2 + 3x + 2 of x ^ 2 + 3x + 6) - (x ^ 2 + 5x + 6 of x ^ 2 + 5x + 2)
（x^2+3X+6）/(x^2+3X+2)=[(x+1)(x+2)+4]/[(x+1)(x+2)]=1+4/[(x+1)(x+2)]
(x^2+5X+2)/(x^2+5X+6)=[(x+2)(x+3)-4]/[(x+2)(x+3)]=1-4/[(x+2)(x+3)]
We can get 4 / [(x + 1) (x + 2)] + 4 / [(x + 2) (x + 3)] by subtraction
And the answer is no mistake: the process of adopting 2X-4 / 4x
What's 29 and a quarter by Four Thirds plus 39 and a fifth by five quarters plus 49 and a sixth by six fifths
29 and a quarter by Four Thirds plus 39 and a fifth by five quarters plus 49 and a sixth by six fifths
=(30-3/4)x4/3+(40-4/5)x5/4+(50-5/6)x6/5
=30x4/3-3/4x4/3+40x5/4-4/5x5/4+50x6/5-5/6x6/5
=40-1+50-1+60-1
=147
Circle x ^ 2 + y ^ 2 + 2ax-2ay + 2A ^ 2-4a = 0 (0
Circle: (x + a) ^ 2 + (Y – a) ^ 2 = 4A can get C: (- A, a) from the point to the tangent, the distance is the radius length can get m - 2A / root 2 = 2 √ 2 square can get (M - 2A) ^ 2 = 8a, so m = 2A - 2 √ (2a) or M = 2A + 2 √ (2a) let √ a = t, t ∈ (0, 2) so m = 2T ^ 2 - 2 √
1. Now a kind of operation *: X * y = XY + X-Y, where x and y are rational numbers (1) find x * y + (Y-X) * 2 (2) find the value of X * y - (x + y) * x, where x = 1, y = 22, the ship sails along the water for 4H and against the water for 2h. It is known that the speed of the ship in still water is a km / h, and the water flow speed is B km / h. how many routes has the ship sailed? When a = 35, B = 5, how many routes has the ship sailed? 3, In the month of last year, the value of electrical appliances in a certain market is 3x-2-y, where the value is 3x-1y, April is 1 billion yuan less than March, may is 20% less than April, and June is 10% less than May. How many billion yuan is the city's electrical appliance export in the second quarter? Is the result 740% a + 128%? If yes, please write the steps and formula again. If not, please add the result and formula. 5. Simplify the following formula (1) 6x-2y + (5x + y) (2) (5a + 3b) - 3 (the square of a-2b) every problem should take steps, formulas and results to be fast, you can add points Oh! Speed to solve it!
1.(1)x*y+(y-x)*2=xy+x-y+2(y-x)+y-x-2=xy+2y-2x-2(2)x*y-(x+y)*x=1*2-3*1=1×2+1-2-（3×1+3-1）=1-5=-42.s=v1t+v2t=(a+b)×4+（a-b)×2=6a+2ba=35,b=5 -->6a+2b=210+10=2203.3xy-(x^2+1/2x^2y)-(xy-x^2y-3)=0.5x^2...
The equation with deformation is expressed as X-1
Let the equation 2 / x-3 / y equal to 1, and use the formula containing x to express that y is y = (3x-3) / 2
How many primes are there in 19, 29, 39, 49, 59, 69
Three