Solve x2 – 8x = 20 by completing the square. which is the solution set of the equation? {–22, 14} {–14, 22} {–10, 2} {–2, 10}

D is the right answer. The solution set of the given equation={-2,10}.

Explanation:

Given equation:

The standard perfect square trinomial equation is

On comparing this with the left side of the given equation ,we get 2a=-8

⇒a= -4 and

Now to make given equation perfect square add 16 on the both sides, we get

Taking square root on both the sides we get,

add 4 on both sides, we get

⇒x= -6+4 or x=6+4

⇒x=-2 or x=10

Therefore, the solution set of the given equation={-2,10}.

Thus D is the right answer.

the answer is 3/5

step-by-step explanation:

first divide 24 divided by 8 because that is the least common multiple

then divide 40 by 8

then you will get 3/5.

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".