Three times the square of a number when added to seven times the number result in 26.the number is?

2 or -

Step-by-step explanation:

Let n be the number then three times the square of the number is 3n² and

seven times the number is 7n, thus

3n² + 7n = 26 ( subtract 26 from both sides )

3n² + 7n - 26 = 0 ← in standard form

Consider the factors of the product of the coefficient of the n² term and the constant term which sum to the coefficient of the n- term

product = 3 × - 26 = - 78 and sum = + 7

The factors are - 6 and + 13

Use these factors to split the n- term

3n² - 6n + 13n - 26 = 0 ( factor the first/second and third/fourth terms )

3n(n - 2) + 13(n - 2) = 0 ← factor out (n - 2) from each term

(n - 2)(3n + 13) = 0

Equate each factor to zero and solve for n

n - 2 = 0 ⇒ n = 2

3n + 13 = 0 ⇒ 3n = - 13 ⇒ n = -

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

the answer is 21%.