WILL GIVE BRAINLIEST, THANKS, AND 5 STARS!!! LOTS OF POINTS! PLEASE SOMEONE HELP ME WITH THESE QUESTIONS!!!!

12. A rectangular kitchen table has an area of 7x^2 + 75x + 50. Which of the following could represent one of the side lengths of the table?
7x + 10
7x + 5
x + 5

13. What number has to fill in the blank to make this a perfect square trinomial: 9x^2 + ___ x + 144.

36
86
18
72

14. Draw an area model to represent 4x^2+12x+9 = (2x+3)^2. Label the length and width of the whole square and label each individual small square and rectangle. (Please submit a picture of the drawn diagram, labeled and all!!!)

PLEASE! And please put good explanations so I understand better!!

Respuesta :

Lenvy

Answer:

[12] 7x+5

[13] 72

Step-by-step explanation:

[12] [tex]7x^2+75+50[/tex]

  • The first term is,  7x^2  its coefficient is  7 .
  • The middle term is,  +75x  its coefficient is  75 .
  • The last term, "the constant", is  +50

First, Multiply the coefficient of the first term by the constant   7 × 50 = 350

Then, find two factors of  350  whose sum equals the coefficient of the middle term, which is  75 .

Then,  Rewrite the polynomial splitting the middle term using the two factors  5  and  70

                    7x^2 + 5x + 70x + 50

Add up the first 2 terms, pulling out like factors :

                   x × (7x+5)

             Add up the last 2 terms, pulling out common factors :

                   10 × (7x+5)

               (x+10)  • (7x+5)

Hence, Answer = 7x + 5

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[13]  

A perfect square trinomial is a quadratic equation of the form

[tex]ax^2+bx+c=0[/tex]  

and a result of squaring a binomial. This means that the first and third term of the trinomial is equal to the square of the first and second term of a binomial. Therefore, in order to determine the value of the third term, we can use the method of completing the square in which the formula is

[tex]c=(\frac{b}{2a})^2[/tex]

where c is the constant and b and a are the coefficients of the first and the second term.

The trinomial 9x^2+72x+144 is a perfect square trinomial, because it's discriminant is equal to zero

Δ=b 2 −4ac=72 2 −4(9)(144)=0  

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~Learn with Lenvy~