Answer:
Step-by-step explanation:
"Find the values of x that satisfy 3x - 2x^2 = 7." Please do not use " × " to represent a variable; " × " is an operator, the "multiply" operator.
Rearrange these three terms in descending order by powers of x:
-2x^2 + 3x - 7 = 0. Here the coefficients are a = -2, b = 3 and c = -7, and so the discriminant of this quadratic is b^2-4ac, or 9 - 4(-2)(-7), or 9 - 56, or -47.
Because the discriminant is negative, we'll have two different complex roots here. The quadratic formula becomes
-3 ± i√47 -3 ± i√47
x = ----------------- = -------------------
2(-2) -4
Given:
Cost of 1 digital song = $1.05
Cost of 2 digital song = $2.10
Cost of 5 digital song = $5.25
To find:
The equation and the cost of 25 downloaded digital songs.
Solution:
Let us take two points (1, 1.05) and (2, 2.10).
Here 
Slope:


m = 1.05
Using point-slope formula:



Add 1.05 on both sides, we get

Here x is the independent variable and c is the dependent variable.
So that substitute x = n and y = c.

The equation is c = 1.05 n.
Substitute n = 25 in the equation.


The cost of 25 songs is $26.25.
EE is a representation of "x10^)
For example,
6EE5 = 
So in this case,

Say b, initial price, + 20,000.
y, price after x years = m years + 20,000.
m would be negative because the price would decline after x years.
Answer: 78 and 80
Step-by-step explanation:
x + (x + 2) = 158
2x + 2 = 158
-2 -2
2x = 156; divide both sides by 2, and you get x = 78
If x = 78, then x + 2 = 80