I’m assuming what you’re asking here is how to *factor* this expression. For that, let’s rearrange the expression into a more familiar form:
-c^2-4c+21
From here, we’ll factor out a -1 so that we have:
-(c^2+4c-21)
Let’s focus on the quadratic expression inside the parentheses. To find our factors (c + x)(c + y), we’ll need to find two terms x and y that multiply together to make -21 and add together to make 4. It turns out that the numbers -3 and 7 work out perfectly for that purpose (-3 x 7 = -21 and 7 + (-3) = 4), so substituting them in for x and y, we have:
(c + (-3))(c + 7)
(c - 3)(c + 7)
And adding back on the negative from a few steps earlier:
-(c - 3)(c + 7)
To solve:
(x-10)(x-10)
Answer: x^2-20x+100
The standard form of a quadratic equation is ,
ax² + bx + c = 0.
And the formula to find the discriminant is b² - 4ac.
Here the first step is to change the given equation into standard form. So, add 1 to each sides of the equation. Therefore,
2x² – 9x + 2+1 = –1 + 1
2x² – 9x + 3 = 0
Next step is to compare the given equation with this equation to get the value of a, b and c.
After comparing the equations we will get a = 2, b = -9 and c = 3.
So, discriminant = b²- 4ac
=( -9)²-4 (2)(3)
= 81 - 24
= 57
So, discriminant of the given equation is 57.
57 is greater than 0 and square root of 57 will result real number.
So, the correct choice is C: The discriminant is greater than 0, so there are two real roots.
Answer:
3.5>3/5
Step-by-step explanation:
