2. write an equation in which the quadratic expression 2x^2-2x-12 equals 0. show the expression in factored form and explain what your solutions mean for the equation. show your work.

step-by-step explanation:

equation

you are asked to write the equation

  expression = 0

using the given expression. when you do that, you have

  2x^2-2x-12 = 0

factoring

you can see that each of the coefficients is even, so a factor of 2 can be removed immediately.

  2(x^2 -x -6) = 0

if you multiply the binomials (x+a)(x+b), you get

  (x +a)(x +b) = x^2 +(a+b)x +ab

this tells you the coefficient of x is the sum of two factors of the constant term. here, that means -1 is the sum of two factors of -6. we want to know those factors so we can factor the trinomial.

  -6 = -1×6 = -2×3 = -3×2 = -6×1

the factor pair that sums to -1 is {-3, 2}, so our factorization is

  2(x -3)(x +2) = 0

solutions

the solutions to this equation are the values of x that make the product zero. a product is zero only when only of the factors of the product is zero. here, that means

  x - 3 = 0

  x = 3 . . . add 3 to both sides of the equation

or

  x +2 = 0

  x = -2 . . . add -2 to both sides of the equation

the solutions to the equation are x=3 or x=-2. both of these values of x satisfy the equation—they make it be true.

The sum of angles in ΔABD is ...

  2a + b + d = 180

The sum of angles in ΔAHG is ...

  a + h + 90 = 180

Solving this second equation for a, we have ...

  a = 180 -90 -h = 90 -h

Substituting this into the first equation, we have ...

  2(90 -h) +b +d = 180

  180 -2h +b +d = 180 . . . . . eliminate parentheses

  b + d = 2h . . . . . . . . . . . . . add 2h-180

  h = (1/2)(b+d) . . . . . . . . . . divide by 2