Answer:
(x, y) = (- 2, 5)
Step-by-step explanation:
given the 2 equations
3y = 11 - 2x → (1)
3x = y - 11 → (2)
Rearrange (2) expressing y in terms of x
add 11 to both sides
y = 3x + 11 → (3)
Substitute y = 3x + 11 into (1)
3(3x + 11) = 11 - 2x
9x + 33 = 11 - 2x ( add 2x to both sides )
11x + 33 = 11 ( subtract 33 from both sides )
11x = - 22 ( divide both sides by 11 )
x = - 2
Substitute x = - 2 in (3) for corresponding value of y
y = (3 × - 2) + 11 = - 6 + 11 = 5
As a check
substitute x = - 2, y = 5 into (1) and (2) and if the left side equals the right side then these values are the solution.
(1) : left side = (3 × 5) = 15
right side = 11 - (2 × - 2) = 11 + 4 = 15 ⇒ left = right
(2) : left side = (3 × - 2 ) = - 6
right side = 5 - 11 = - 6 ⇒ left = right
solution = (- 2, 5 )
Area A Output: 2, 4, 6, 8
Perimeter P Output: 6, 8, 10, 12
Explanation: Just replace the x with the inputs and then solve.
Answer:
Amanda's box volume is 70 cm^3 greater than Mary's
Step-by-step explanation:
Find and then compare the volumes of the two boxes:
Amanda's: 10*10*13.5 cm^3 = 1350 cm^3
Mary's: 8*8*20 = 1280 cm^3
Amanda's box volume is 70 cm^3 greater than Mary's.
Let's call our estimate x. It will be the average of n IQ scores. Our average won't usually exactly equal the mean 97. But if we repeated averages over different sets of tests, the mean of our estimate the average would be the same as the mean of a single test,
μ = 97
Variances add, so the standard deviations add in quadrature, like the Pythagorean Theorem in n dimensions. This means the standard deviation of the average x is
σ = 17/√n
We want to be 95% certain
97 - 5 ≤ x ≤ 97 + 5
By the 68-95-99.7 rule, 95% certain means within two standard deviations. That means we're 95% sure that
μ - 2σ ≤ x ≤ μ + 2σ
Comparing to what we want, that's means we have to solve
2σ = 5
2 (17/√n) = 5
√n = 2 (17/5)
n = (34/5)² = 46.24
We better round up.
Answer: We need a sample size of 47 to be 95% certain of being within 5 points of the mean
Answer:
48+6= 54
54/2= 27
Answer is 27
Step-by-step explanation:
