Let's first write the equation given
x²+6x-13=0
They have told us to use "Completing the square" method.
So we need write x²+6x-13 as a whole square.
x²+6x-13=0
x²+(2*3*x)-9-4 = 0
x²+(2*3*x)-3²=4
Now we can write the LHS as:
(x - 3)²=2²
Hence,
x-3 can either be 2 or -2
Now,
x - 3=2
x=5
Or,
x - 3=-2
x=1
Therefore now we know that x can either be 1 or 5. So the correct answer is Option B.
Answer:
$290
Step-by-step explanation:
We are told that 1 out of 5 buyers change to a more expensive sofa than the one in the sale advertisement.
Now we are told that the advertised sofa is $250 and the more expensive sofa is $450.
Thus;
P(x) for expensive sofa = 1/5
P(x) for sofa in sale advertisement = 4/5
Thus, expected value is;
E(X) = (1/5)450 + (4/5)250
E(x) = 90 + 200
E(x) = $290
I I'm guessing true if you don't think so then don't take my advice.
P(x)=f(x)*g(x)
P(x)=(x-400)(1,200-2x)
P(x)=1,200x-2x^2-480,000+800x
P(x)=-2x^2+2,000x-480,000
Answer: Option <span>D. P(x) = -2x2 + 2,000x - 480,000</span>