(a+b)(a-b)=a^2 - b^2
so
<span>(4x-7)(4x+7) = 16x^2 - 49
answer
</span>16x^2 - 49
Answer:
39. 29
36. 50
33. 7
30. 33
Step-by-step explanation:
39. According to the Order of Operations, in this case, Subtraction & Addition are evaluated after Division & Multiplication:
36. Evaluate everything since everything is wrapped in parentheses:
33. Evaluate everything inside of parentheses FIRST:
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Answer:
We have strong evidence that on average, students study less than 150 minutes per night during the school week
Step-by-step explanation:
Normal distribution:
mean μ₀ = 150
Sample:
Sample size n = 272
Sample mean x = 141
Sample standard deviation s = 66
The standard error of the sample mean SE = σ /√n
SE = 66/√272
SE = 66 / 16,49
SE = 4
Test Hypothesis:
Null hypothesis H₀ x = μ₀
Alternative hypothesis Hₐ x < μ₀
z(s) test statistics is:
z(s) = ( x - μ₀ ) / s/√n
z(s) = - 9 /4
z(s) = - 2,25
p-value for that z(s) p-value = 0,0122
Then for α = 0,05 p-value < 0,05
We are in the rejection region we need to reject H₀
