Factored form is whenever we have two or more expressions being multiplied like you see here. A more simpler example may be breaking 36 into 12*3, or 36 = 12*3. We say that 12*3 is the factored form of 36. The two pieces 12 and 3 multiply to 36.
Standard form for quadratics is ax^2 + bx + c. The exponents count down: 2,1,0. You can think of it as ax^2 + bx^1 + cx^0. In this case, a = 2, b = 1, c = -3.
The y intercept always occurs when x = 0. Plugging this value in leads to y = -8. The y intercept is located at (0,-8). The last value at the end, the constant term, is always the y intercept. This is one handy feature of standard form quadratic equations.
The parent function of any quadratic is always y = x^2. From this parent function, we can derive any scaled version in the form y = ax^2, and we can also apply shifting to get y = (x-h)^2 or y = x^2+k. All together, we can generate y = a(x-h)^2 + k to represent both scaling and shifting. That last equation is vertex form which can convert to standard form shown in choice C.
There are two solutions and the solutions are x = -5 and x = 5. Note how x^2 = (5)^2 = 25 and x^2 = (-5)^2 = 25. The two negatives cancel out when we multiply. Be sure to have the negative inside the parenthesis. We don't say -(5)^2 = -25.
