David wants to hang a mirror in his room. the mirror and frame must have an area of 8 square feet. the mirror is 2 feet wide and 3 feet long. which quadratic equation can be used to determine the thickness of the frame, x?

2x2 + 14x − 2 = 0
3x2 + 10x − 8 = 0
4x2 + 10x − 2 = 0
x2 + 7x − 8 = 0

Represent the thickness of the frame by x. Framing the mirror will increase both its length and width by 2x. The area of the mirror with the frame is the product of the length and width which can mathematically be expressed as,                                 

                                               A = (3 + 2x)(2 +2x) = 8

The equation above can be simplified into 4x^2 + 10x -2 = 0. This equation can still be further simplified by dividing it by 2. However, it will give an answer which is not found on the choices. Thus, the answer is the third choice. 

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc