Add 2x^2 to both sides
7x^2-2x-6=9x
Subtract 9x from both sides
7x^2-11x-6=0
Factor by using slip and slide
x^2-11x-42
(x-14)(x+3)
(x-14/7)(x+3/7)
(x-2)(7x+3)
Then use the Zero Product Property to find roots
x-2=0
x=2
7x+3=0
7x=-3
x=-3/7
Final answer: x=-3/7, x=2
Answer:
a) when x = Raw Score: 42
Standard deviation = σ = -10.3
b) Raw Score: 81
Standard deviation = σ = 2.67
Step-by-step explanation:
Find the standard deviation if the mean of a sample is 72, a z-score of 3
Z score formula is given :
z = (x-μ)/σ,
where
x is the raw score
μ is the population mean = 73
σ is the population standard deviation
z = 3
a) when x = Raw Score: 42
z = (x-μ)/σ
3 = 42 - 73/σ
Cross Multiply
3σ = 42 - 73
3σ = -31
σ = -31/3
σ = -10.3
b) Raw Score: 81
z = (x-μ)/σ
3 = 81 - 73/σ
Cross Multiply
3σ = 81 - 73
3σ = 8
σ = 8/3
σ = 2.67
4 significant figures.
Step-by-step explanation:
<h2>:)</h2>
The answer is 80sq.ft... to figure this out, you just multiply both sides together
