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
Answer:
A
Explanation:
has properties that are different from the original substances.
d. exothermic; leaving
- Exothermic reaction is a reaction that produces heat in the reaction whereas the endothermic reaction is a reaction in which heat is required to be given in the reaction to produce product.
- Fire is an exothermic reaction.
- A fire is produced due to oxidation of the fuel in the form of liquid or gas.
- A fire is an example of combustion.
- In fire both heat and light are left from fire due to the oxidation of fuel.
Hence, option d. exothermic; leaving is the correct option.
Learn more about fire:
brainly.com/question/12761984
Answer: M = 2.08 M
Explanation: Molarity is expressed as the number of moles per unit volume in liters. First convert the mass of HCl to moles using its molar mass. Then substitute the variables to the formula for molarity.
75.00 g HCl x 1 mole HCl / 36 g HCl
= 2.08 moles HCl
For Molarity.
M = n / L
= 2.08 moles HCl / 1.000 L
= 2.08 M