Answer:
x = 1, -7.5
Explanation:
2x² + 13x = 15
Divide the left side of the equation by 2
2(x² + 6.5x) = 15
Divide 6.5 by 2 and square the quotient
6.5/2 = 3.25
3.25² = 10.5625
Add 10.5625 to the left side
2(x² + 6.5x + 10.5625) = 15
Since you have a 2 outside the parentheses, you will be adding 10.5625•2 to the right side.
10.5625 • 2 = 21.125
2(x² + 6.5x + 10.5625) = 36.125
To factor (x² + 6.5x + 10.5625), add b/2 to x
b/2 = 6.5/2 = 3.25
2(x + 3.25)² = 36.125
Divide by 2
(x + 3.25)² = 18.0625
Square root.
(x + 3.25) = √18.0625
x + 3.25 = ±4.25
Subtract 3.25.
x = 4.25 - 3.25 = 1
x = -4.25 - 3.25 = -7.5
x = 1, -7.5
Yes you add water to calcium oxide it makes calcium hydroxide
they all have one thing in common and that its all made up of atoms. When these components are active it creates energy
Answer : The concentration of solution is, 8.53 M.
Explanation :
As we are given, 45.0 mass % solution of ethanol in water that means 45.0 g of ethanol present in 100 g of solution.
First we have to calculate the volume of solution.
Now we have to calculate the molarity of solution.
Mass of 
= 45.0 g
Volume of solution = 114.5 mL
Molar mass of = 46.07 g/mole
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :
Now put all the given values in this formula, we get:
Therefore, the concentration of solution is, 8.53 M.
Answer:
Well yes and no
Explanation:
The molecules move, but in place. They are constantly vibrating, rotating and so forth.
Atoms do not move at all
