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PLS ANSWER IN THIS MATH

PLS ANSWER IN THIS MATH-example-1
User Marenz
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2 Answers

2 votes

Question 1.

The dimensions of the rectangle is given as 3x-5 by 2x+8.

The perimeter of a rectangle is given by:


P= 2(l + w)

We substitute the dimensions to get:


P= 2(3x - 5 + 2x + 8)

We simplify to obtain:


P= 2(5x + 3)


P= 10x + 6

If each foot costs $5 then x feet will cost 5x dollars.

Therefore the total cost of fencing will be;


10(5x) + 6 * 5= 50x + 30

The total cost in terms of x is 50x+30

Question 2.

The area of the rectangle is given as


{x}^(2) - 2x - 35

We can factor to find the possible dimensions of this rectangle.

We split the middle term to get:


{x}^(2) + 5x - 7x - 35

We factor by grouping:


x(x +5 ) - 7(x + 5)

We factor further to get:


(x - 7)(x + 5)

The possible dimensions are x-7 by x+5

User Vanagar
by
3.6k points
6 votes

Question # 1

Answer:

It would cost
50x+30 dollars to put fencing around this garden.

Explanation:

In Linda's garden each side is:

  • either
    3x-5 feet or
    2x+8 feet

so

We need to determine the perimeter of the rectangle in order to figure out how much fencing there is.


P=\left(3x-5\right)+\left(2x+8\right)+\left(3x-5\right)+\left(2x+8\right)

As price per foot of fencing is 5 dollars.

So multiply this by 5 dollars.


5\left(P\right)=5\left[\left(3x-5\right)+\left(2x+8\right)+\left(3x-5\right)+\left(2x+8\right)\right]

solving


5\left[\left(3x-5\right)+\left(2x+8\right)+\left(3x-5\right)+\left(2x+8\right)\right]


=5\left(\left(3x-5\right)+\left(2x+8\right)+\left(3x-5\right)+\left(2x+8\right)\right)


\mathrm{Remove\:parentheses}:\quad \left(a\right)=a


=5\left(3x-5+2x+8+3x-5+2x+8\right)...[A]


\mathrm{Simplify}\:3x-5+2x+8+3x-5+2x+8


3x-5+2x+8+3x-5+2x+8


=3x+2x+3x+2x-5+8-5+8


=10x-5+8-5+8


=10x+6

so Equation [A] becomes


=5\left(10x+6\right)


=50x+30

Therefore, it would cost
50x+30 dollars to put fencing around this garden.

Question # 2

Answer:

The possible dimensions of the rectangle are
\left(x-5\right)\left(x+7\right).

Explanation:

As the rectangle has the area =
x^2+2x-35

As

Area = Length × Width

The dimensions of the rectangle could be found by factoring the area:


x^2+2x-35


\mathrm{Break\:the\:expression\:into\:groups}


=\left(x^2-5x\right)+\left(7x-35\right)


\mathrm{Factor\:out\:}x\mathrm{\:from\:}x^2-5x\mathrm{:\quad }x\left(x-5\right)


\mathrm{Factor\:out\:}7\mathrm{\:from\:}7x-35\mathrm{:\quad }7\left(x-5\right)


=x\left(x-5\right)+7\left(x-5\right)


\mathrm{Factor\:out\:common\:term\:}x-5


=\left(x-5\right)\left(x+7\right)

Therefore, the possible dimensions of the rectangle are
\left(x-5\right)\left(x+7\right).

User Aysel
by
3.1k points