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
How to calcutate concentration of solution.
there is 12gram of solute in a 36 gram solution
then you take 12 divided by 24 because 36-12=24 which is youe solvent
Answer:
112.22 g
Explanation:
mass = no. of moles x atomic mass
From the periodic table, we can see the atomic mass of Ca is 40.078.
Therefore,
mass = 2.80 x 40.078
= 112.22g (corrected to 2 decimal places.)
Answer:

Explanation:
Hello,
In this case, is possible to infer that the thermal equilibrium is governed by the following relationship:

Thus, both iron's and water's heat capacities are: 0.444 and 4.18 J/g°C respectively, so one solves for the mass of water as shown below:

Best regards.
Sand dunes would be created due to the mixture falling on each other
x