X = 20
First, you move the 40 to the other side.
-2x=-40
Then, you divided -40 by -2.
x= -40/-2
x= 20
x is 20 because the negatives cancel out making it positive.
So first you have to find the perfect square that matches up with x^2 + 6x
so half of 6, and square it. your perfect square is 9
x^2 + 6x + 9 = 7 + 9
then, condense the left side of the equation into a squared binomial:
(x + 3)^2 = 16
take the square root of both sides:
x + 3 = ± √16
therefore:
x + 3 = ± 4
x = - 3 ± 4
so your solution set is:
x = 1, -7
Answer:
about 11.03 million
Step-by-step explanation:
Use the equation I = P(1+r/100)^n - P (I is the compound interest, P is the principle, r is the rate percent, and n is the number of years):
Substitute the values given:
I = 70,000,000(1 + 5/100)^3 - 70,000,000
Use a calculator to solve and you will get ~11.03 million.
<span>The number of dollars collected can be modelled by both a linear model and an exponential model.
To calculate the number of dollars to be calculated on the 6th day based on a linear model, we recall that the formula for the equation of a line is given by (y - y1) / (x - x1) = (y2 - y1) / (x2 - x1), where (x1, y1) = (1, 2) and (x2, y2) = (3, 8)
The equation of the line representing the model = (y - 2) / (x - 1) = (8 - 2) / (3 - 1) = 6 / 2 = 3
y - 2 = 3(x - 1) = 3x - 3
y = 3x - 3 + 2 = 3x - 1
Therefore, the amount of dollars to be collected on the 6th day based on the linear model is given by y = 3(6) - 1 = 18 - 1 = $17
To calculate the number of dollars to be calculated on the 6th day based on an exponential model, we recall that the formula for exponential growth is given by y = ar^(x-1), where y is the number of dollars collected and x represent each collection day and a is the amount collected on the first day = $2.
8 = 2r^(3 - 1) = 2r^2
r^2 = 8/2 = 4
r = sqrt(4) = 2
Therefore, the amount of dollars to be collected on the 6th day based on the exponential model is given by y = 2(2)^(5 - 1) = 2(2)^4 = 2(16) = $32</span>