Answer:
9
Step-by-step explanation:
7r+18=r²
r²-7r-18=0
factorizing
r²+2r-9r-18=0
r(r+2)-9(r+2=0
(r-9)(r+2)=0
r-9=0
r=9
check
(r²)=(9*9)=81
7r+18=7(9) + 8=81
Answer:
6n^2+3n+8
Step-by-step explanation:
simplify like terms. keep the exponent the same degree it started as
Answer:
x = 1 + sqrt(89) or x = 1 - sqrt(89)
Step-by-step explanation:
Solve for x:
(x - 9) (x + 7) = 25
Expand out terms of the left hand side:
x^2 - 2 x - 63 = 25
Add 63 to both sides:
x^2 - 2 x = 88
Add 1 to both sides:
x^2 - 2 x + 1 = 89
Write the left hand side as a square:
(x - 1)^2 = 89
Take the square root of both sides:
x - 1 = sqrt(89) or x - 1 = -sqrt(89)
Add 1 to both sides:
x = 1 + sqrt(89) or x - 1 = -sqrt(89)
Add 1 to both sides:
Answer: x = 1 + sqrt(89) or x = 1 - sqrt(89)
Rounded to the nearest tenth, the square root of 149 is 12.2.
Answer:
a) 0.9964
b) 0.3040
Step-by-step explanation:
Given data:
standard deviation = $90,000
Mean sales price =$345,800
sample mean = $370,000
Total number of sample = 100
calculate z score for [/tex](\bar x = 370000)[/tex]
z = 2.689
P(x<370000) = P(Z<2.689)
FROM STANDARD NORMAL DISTRIBUTION TABLE FOR Z P(Z<2.689) = 0.9964
B)
calculate z score for (\bar x = 350000)
z = 2.133
FROM NORMAL DISTRIBUTION TABLE Z VALUE FOR
SO, = 0.9836 - 0.6796 = 0.3040
