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2 years ago

5. Simplify the expression and find its value when p= 4 and q = -5:

Mathematics

2 answers:

Ierofanga [76]2 years ago

7 0

<u>Answer</u>: -180

Step-by-step explanation:

$\bf \blue{ \boxed{ \bf p = 4 \: \: and \: \: q = - 5 \Rightarrow pq = 4 \times ( - 5) = - 20}}$

3(p2q + pq2 - pq) - 6pq + 3pq2 =

3[-20 × 2 + (-20) × 2 - (-20)] - 6 × (-20) + 3 × 2 × (-20) =

3[-40 + (-40) + 20] - 6 × (-20) + 3 × 2 × (-20) =

3(-40 - 40 + 20) - 6 × (-20) + 3 × 2 × (-20) =

3(-80 + 20) - 6 × (-20) + 3 × 2 × (-20) =

3 × (-60) - 6 × (-20) + 3 × 2 × (-20) =

-180 + 120 + 6 × (-20) =

-180 + 120 + (-120) =

-180 + 120 - 120 =

-60 - 120 = -180

Andrei [34K]2 years ago

7 0

Answer:

-180

Step-by-step explanation:

3 ( p2q + Pq2 - pq ) - 6 pq +3pq2

3 [(4)(2)(-5) + (4)(-5)(2) - (4)(-5)] -6 (4)(-5) +3(4)(-5)(2)

3(-40-40+20) + 120 -120

3(-60) +0

-180+0

-180

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3 years ago

A researcher compares the effectiveness of two different instructional methods for teaching physiology. A sample of 178 students

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critical value = 1.645

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Step-by-step explanation:

Given that:

the sample size $n_1$ = 178

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the sample mean $\overline x_1$ = 54.4

the sample mean $\overline x_2$ = 74.5

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population standard deviation $\sigma_2$ = 9.52

level of significance ∝ = 1 - 0.90 = 0.10

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For the construction of our confidence interval, we use 90% since that is used to find the critical value.

∴

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$1.645 \times\sqrt{\dfrac{18.58^2}{178} + \dfrac{9.52^2}{226}}$

$1.645 \times\sqrt{\dfrac{345.2164}{178} + \dfrac{90.6304}{226}}$

$1.645 \times\sqrt{2.34042}$

$\simeq$ 2.52

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