X square + 12x + 27 = 0

X square + 12x + 27 = 0

x^2+12x+27=0
(x+3)(x+9)=0
X = - 3 or x = - 9

7 of (x's square + x) + 1 of (x's square-x) equals 6 of (x's Square-1)

7/(X²+X) + 1/(X²-X) = 6/(X²-1)7/(X+1) + 1/(X-1) = 6X/(X²-1){ 7(X-1) + (X+1) } / (X²-1) = 6X/(X²-1)7(X-1) + (X+1) = 6X7X - 7 + X + 1 = 6X8X - 6 = 6X2X - 6 = 0X = 3

Train a runs for 10 hours and train B runs for 7 hours. Train a runs 276 kilometers more than train B. if the two trains have the same speed, find the speed of the two trains

276/(10-7)=92
Their speed is 92 km / h

How many square meters of iron sheet should be used to make 24 rectangular iron sheet chimneys, each of which is 2 meters long, 4 decimeters wide and 3 decimeters high?

Because 4 decimeters = 0.4 meters, 3 decimeters = 0.3 meters, then (0.4 × 2 + 0.3 × 2) × 2 × 24 = (0.8 + 0.6) × 2 × 24 = 1.4 × 2 × 24 = 2.8 × 24 = 67.2 square meters

How to calculate the sectional area of triaxial cement mixing pile? For example, the pile diameter is 850 and the pile wheelbase is 600

You can first draw a pair of triaxial mixing piles in CAD, and then select "area" on the drawing tool bar - select the figure to calculate the area - enter, you can see that all sides of the figure are combined together - enter "area" in the command line, enter "O" in turn - select the figure, enter is OK. The area is 1.49 square meters

The volume sum of cone and cylinder with equal base and height is 12.56 cubic decimeter, and the volume of cone is () cubic decimeter
A. 3.14B. 6.28C. 12.56D. 25.12

A: the volume of a cone is 3.14 cubic decimeter

A number is not only a factor of 30, but also a multiple of 5. What is the minimum two digit number?

10
It's a multiple of 5, so it's 5, 10, 15, etc
It's a factor of 30, so it's 1, 3, 5, 6, 10, 15, 30
Therefore, the minimum two digits is 10

Finding the difference between 4ab-2b square + 7a square and 2a-ab + 3B square

(4ab-2b²+7a)-(2a²-ab+3b²)
=4ab-2b²+7a-2a²+ab-3b²
=5ab-5b²+7a-2a²
=-2a²+7a+5ab-5b²

When you raise your hand, the arm is the object exerting the force, and the hand is the object receiving the force. Why

As you raise your hand, the muscles of your arms contract to produce force and lift it

{y=2+x {3x+2y=19

Substituting y = 2 + X into x = 3, y = 5 of the solution 3x + 2Y = 19