What form of deductive reasoning is used in this argument? If a triangle is scalene, it has no sides the same length. If a triangle has no sides the same length, then it isn't equilateral. If a triangle is scalene, then it isn't equilateral. A. law of detachment B. law of syllogism C. law of contrapositive D. law of converse E. identification of counterexample

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0