Answer:
4 days
Step-by-step explanation:
268-112= 156
156 divided by 39 = 4
Quadratic equations CAN be used to solve word problems so the answer to your question is false
<span>A medical researcher wants to investigate the amount of time it takes for patients' headache pain to be relieved after taking a new prescription painkiller. She plans to use statistical methods to estimate the mean of the population of relief times. She believes that the population is normally distributed with a standard deviation of 18 minutes. How large a sample should she take to estimate the mean time to within 4 minutes with 97% confidence?
-----
n = [z*s/E]^2
---
n = [2.17*18/4]^2 = 96 when rounded up
</span>
Answer:
(4,3)
Step-by-step explanation:
Given
x^2+y^2=25
x-y^2=-5
In order to solve the equations, from equation 2 we get
-y^2= -5-x
y^2=5+x
Putting the value of y^2 in equation 1
x^2+5+x=25
x^2+5-25+x=0
x^2+x-20=0
x^2+5x-4x-20= 0
x(x+5)-4(x+5)=0
(x+5)(x-4)=0
So
x+5=0 x-4=0
x=-5 x=4
Now for x=-5
x^2+y^2=25
(-5)^2+y^2=25
25+y^2=25
y^2=25-25
y^2=0
so Y=0
And for x = 4
x^2+y^2=25
(4)^2+y^2=25
16+y^2=25
y^2=25-16
y^2=9
y= ±3
So the solution to the system of equations is
(-5,0) , (4,3), (4,-3)
The only solution that belongs to first quadrant is (4,3)
Answer:130 I think I’m not real sure
Step-by-step explanation:
