10, 20, 30, 40, 50, 60, 70, 80, 90, 100
3x^2 + 21x
Is the answer without a doubt.
1. n^2 -8n +16 = 25
Subtract 25 from both sides
n^2 - 8n + 16 - 25 = 0
Simplify
n^2 - 8n - 9 =0
Factor
(n-9)(n+1) = 0
Solve for n
n-9 = 0, n = 9
n+1 = 0, n = -1
Solution: 9,-1
2. C = b^2/25
Multiply both sides by 25:
25c = b^2
Take square root of both sides
b = +/-√25c
Simplify:
b = 5√C, -5√C
3. d = 16t^2 +12t
subtract d from both side:
16t^2 + 12t -d =0
Use quadratic formula to solve:
t = (3 +/-√(9-4d))/8
4. 5w^2 +10w =40
Subtract 40 from both side:
5w^2 + 10w -40 = 0
Factor:
5(w-2)(w+4)=0
Divide both sides by 5:
(w-2)(w+4)=0
Solve for w:
w-2 = 0, w = 2
w+4=0, w = -4
Solution: 2,-4
Answer:
x= -5/2
Step-by-step explanation:
4 - (2x+4)=5
4-2x-4=5
-2x=5
x=-5/2
Answer:
0.9544
Step-by-step explanation:
We are given that mean=18 and standard deviation=1 and we have to find P(16<X<20).
P(16<X<20)=P(z1<Z<z2)
z1=(x1-mean)/standard deviation
z1=(16-18)/1=-2
z2=(x2-mean)/standard deviation
z2=(20-18)/1=2
P(16<X<20)=P(z1<Z<z2)=P(-2<Z<2)
P(16<X<20)=P(-2<Z<0)+P(0<Z<2)
P(16<X<20)=0.4772+0.4772=0.9544
The probability that the height of a tree is between 16 and 20 feet is 95.44%
