-6a - 4a + 7a = -10a + 7a = -3a, that isn't 5a;
b. False
Answer:
To find the percetage of data points that lie between the points -3.01 and 2.61, on a normal distribution we're going to need the help of a calculator. The result is: 99.42%
Attached you will find the graph that represents the result.
If you add them straight down:
2d-e = 7
d + e = 5
Then the e's cancel out.
You are left with 3d = 12
Then solve for d by dividing each side by 3.
Now you have d =4.
To solve for e go back into one of your original equations and substitute 4 for the d.
You can use either equation, so I'll choose the second one.
4 + e = 5
Now solve for e by subtracting each side by 4.
Now you have e = 1.
So your solutions are d = 4 and e = 1
(x^2-9)(x^3-8)=0
as you can see that (x^2-9) is in the form of a^2 - b^2 which equals (a+b)(a-b)
x^2 - 9
= (x)^2 -(3)^2
= (x+3)(x-3)
now, the equation becomes
(x+3)(x-3)(x^3-8)=0
(x+3) =0
x = -3
(x-3) = 0
x = 3
x^3 -8 = 0
x^3 = 8
x = cube rt. 8
= 2
so, the three solutions are -3, 3 and 2.
