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2 years ago

(2x + 7y) (4x – 8y)

Mathematics

1 answer:

Shtirlitz [24]2 years ago

3 0

Answer:

= 8x^2 + 12xy − 56y^2

Step by step:

(2x+7y)(4x−8y)

=(2x+7y)(4x+−8y)

=(2x)(4x)+(2x)(−8y)+(7y)(4x)+(7y)(−8y)

=8x^2−16xy+28xy−56y^2

=8x^2+12xy−56y^2

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What is the value of the expression (3/4)³ 81/256 27/64 9/12 27/4

anzhelika [568]

Answer:

9/12

Step-by-step explanation:

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1 year ago

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4. Gloria the grasshopper is working on her hops.

aivan3 [116]

The path that Gloria follows when she jumped is a path of parabola.

The equation of the parabola that describes the path of her jump is $\mathbf{y = -\frac{5}{49}(x - 14)^2 + 20}$

The given parameters are:

$\mathbf{Height = 20}$

$\mathbf{Length = 28}$

Assume she starts from the origin (0,0)

The midpoint would be:

$\mathbf{Mid = \frac 12 \times Length}$

$\mathbf{Mid = \frac 12 \times 28}$

$\mathbf{Mid = 14}$

So, the vertex of the parabola is:

$\mathbf{Vertex = (Mid,Height)}$

Express properly as:

$\mathbf{(h,k) = (14,20)}$

A point on the graph would be:

$\mathbf{(x,y) = (28,0)}$

The equation of a parabola is calculated using:

$\mathbf{y = a(x - h)^2 + k}$

Substitute $\mathbf{(h,k) = (14,20)}$ in $\mathbf{y = a(x - h)^2 + k}$

$\mathbf{y = a(x - 14)^2 + 20}$

Substitute $\mathbf{(x,y) = (28,0)}$ in $\mathbf{y = a(x - 14)^2 + 20}$

$\mathbf{0 = a(28 - 14)^2 + 20}$

$\mathbf{0 = a(14)^2 + 20}$

Collect like terms

$\mathbf{a(14)^2 =- 20}$

Solve for a

$\mathbf{a =- \frac{20}{14^2}}$

$\mathbf{a =- \frac{20}{196}}$

Simplify

$\mathbf{a =- \frac{5}{49}}$

Substitute $\mathbf{a =- \frac{5}{49}}$ in $\mathbf{y = a(x - 14)^2 + 20}$

$\mathbf{y = -\frac{5}{49}(x - 14)^2 + 20}$

Hence, the equation of the parabola that describes the path of her jump is $\mathbf{y = -\frac{5}{49}(x - 14)^2 + 20}$

See attachment for the graph

Read more about equations of parabola at:

brainly.com/question/4074088

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1 year ago

I need help with this math problem plz help and plz explain your answer

IceJOKER [234]

Answer:

34.04 cm²

Step-by-step explanation:

Formula for a trapezoid:

a + b ÷ 2 × height

Substitute the values:

11.7 + 3.1 = 14.8

14.8 ÷ 2 = 7.4

7.4 × 4.6 = 34.04

The answer is 34.04 cm²

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2 years ago

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Maddie has 4 cups of maple syrup. She uses 1/3 of the syrup to make maple candies. Then, she uses 2/3 of a cup of syrup to make

Reptile [31]

Answer:

3 cups

Step-by-step explanation:

1/3 + 2/3 = 1 cup so you would subract 1 from 4 which is 3

hope this helps:)

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2 years ago

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During a scuba dive, Lainey descended to a point 19 feet below the ocean surface. She continued her descent at a rate of 25 feet

Leno4ka [110]

Answer:

$25t+19\leq 144$

$t\leq5$

The number of minutes she can continue to descend if she does not want to reach a point more than 144 feet below the ocean surface is at most 5 minutes.

Step-by-step explanation:

Given:

Initial depth of the scuba dive = 19 ft

Rate of descent = 25 ft/min

Maximum depth to be reached = 144 ft

Now, after 't' minutes, the depth reached by the scuba dive is equal to the sum of the initial depth and the depth covered in 't' minutes moving at the given rate.

Framing in equation form, we get:

Total depth = Initial Depth + Rate of descent × Time

Total depth = $19+25t$

Now, as per question, the total depth should not be more than 144 feet. So,

$\textrm{Total depth}\leq 144\ ft\\\\19+25t\leq 144\\\\or\ 25t+19\leq 144$

Solving the above inequality for time 't', we get:

$25t+19\leq 144\\\\25t\leq 144-19\\\\25t\leq 125\\\\t\leq \frac{125}{25}\\\\t\leq 5\ min$

Therefore, the number of minutes she can continue to descend if she does not want to reach a point more than 144 feet below the ocean surface is at most 5 minutes.

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2 years ago