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3 years ago

find an expression for the area of a rectangle of sides 2x+3 and x-1 given that the perimeter is 28cm what is the value of x

Mathematics

1 answer:

Ierofanga [76]3 years ago

4 0

Answer:

4cm

Step-by-step explanation:

Given data

L=(2x+3)

W=(x-1)

P=28cm

A= L*W

A= (2x+3)*(x-1)

open bracket

A= 2x^2-2x+3x-3

collect like terms

A= 2x^2+x-3

P= 2L+2W

P= 2*(2x+3)+2(x-1)

P= 4x+6+2x-2

collect like terms

P= 6x-4

but p= 28

28= 6x-4

28-4= 6x

24= 6x

x= 24/6

x= 4cm

Hence x= 4cm

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Vladimir79 [104]

Answer:

The value of x that maximizes the volume enclosed by this box is 0.46 inches

The maximum volume is 3.02 cubic inches

Step-by-step explanation:

see the attached figure to better understand the problem

we know that

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substitute

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Convert to expanded form

$V=(7-2x)(2-2x)x\\V=(14-14x-4x+4x^{2})x\\V=14x-14x^2-4x^2+4x^{3}\\V=4x^{3}-18x^{2} +14x$

using a graphing tool

Graph the cubic equation

Remember that

The domain for x is the interval -----> (0,1)

Because

If x>1

then

the width is negative (W=2-2x)

The maximum is the point (0.46,3.02)

see the attached figure

therefore

The value of x that maximizes the volume enclosed by this box is 0.46 inches

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8 0

3 years ago

I really need help on this !!

Naddik [55]

Answer:

r = -1

Step-by-step explanation:

(y2-y1)/(x2-x1)=m

(r,7)=(x1,y1) and (3,4)=(x2-y2) and m=-3/5

so plug in...

(4-7)/(4-r)=-3/5

then solve for r which will get that r = -1

numerator: 4-7=-3

denominator: 4-r=5 -> 4-5=0+r -> -1=r

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3 years ago

9(2a+2) equivalent expression

ollegr [7]

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Which graph represents the line that has a -intercept of 3 and goes through the point (2, 5) ?

Jobisdone [24]

Answer:

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Step-by-step explanation:

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Read 2 more answers

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scZoUnD [109]

Set up equal ratios

t/6=0.75/4.5 multiply both sides by 6

t=4.5/4.5

t=1 hour

So it will take Madison one hour to ride another six miles.

5 0

3 years ago