Answer:
3 (5x+2y = 0)
2 (2x – 3y = -19)
Step-by-step explanation:
5x+2y=0 (1)
2x-3y=-19 (2)
To eliminate y from the first two equation when applying the linear combination method
We will multiply y Equation (1) and (2) with 3 and 2 respectively so that the coefficients of y in the two equations +6 and -6 respectively
3(5x+2y=0)
2(2x-3y=-19)
We have,
15x+6y=0 (3)
4x-6y= -38 (4)
Add Equation (3) and (4)
19x=-38
x= -2
Substitute x= -2 into (1)
5x+2y=0
5(-2)+2y=0
-10+2y=0
-10= -2y
y=-10/-2
=5
y=5, x=-2
Answer:
none of the above
Step-by-step explanation:
The grocer's revenue will be the product of the number of loaves sold (30-2x) and their price (2.50+0.50x).
Revenue will be positive for values of x between those that make these factors be zero. The number of loaves sold will be zero when ...
... 30 -2x = 0
... 15 -x = 0 . . . . . divide by 2
... x = 15 . . . . . . . add x
The price of each loaf will be zero when ...
... 2.50 +0.50x = 0
... 5 + x = 0 . . . . . . . multiply by 2
... x = -5 . . . . . . . . . . subtract 5
Revenue will be positive for any number of increases greater than -5 and less than 15.
_____
D is the best of the offered choices, but it is incorrect in detail. -5 is a number less than 15, but will give zero revenue.
Answer:



Step-by-step explanation:
Given
Let
A = Event of being a universal donor.
So:


Solving (a): Mean and Standard deviation.
The mean is:



The standard deviation is:




Solving (b): P(x = 3)
The event is a binomial event an dthe probability is calculated as:

So, we have:




Answer:
k=2
Problem:
if the equation x^2 +(k+2)x+2k=0 has equal roots,then the value of k is ..
Step-by-step explanation:
Since the coefficient of x^2 is 1, we can use this identity to aid us: x^2+bx+(b/2)^2=(x+b/2)^2.
So we want the following:
[(k+2)/2]^2=2k
Apply the power on the left:
(k+2)^2/4=2k
Multiply both sides by 4:
(k+2)^2=8k
Expand left side:
k^2+4k+4=8k *I used identity (x+c)^2=x^2+2xc+c^2
Subtract 8k on both sides:
k^2-4k+4=0
Factor using the identity mentioned a couple lines above:
(k-2)^2=0
Since zero squared is zero, we want k-2=0.
Adding both sides by 2 gives k=2.
Answer:
7500
Step-by-step explanation: