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7. Okay. So the computer was originally $1,080, and the discount is 20%, but David would still have to pay 80% of the original price. To find the sale price, let's multiply. 1,080 * 80% (0.8) is 864. The sale price of the compuet is $864, but now we must add the sales tax to find the total price. We will multiply by 108%, because 100% (representing the price + 8% is 108%, and doing this will get us stright to the total price. 864 * 108% (1.08) is 933.12. There. David paid a total price of $933.12 for the computer.
8. Okay. So we are looking for the amount of discount for the sweater Suzanne bought. First off, let's subtract the prices to find the difference. 40 - 25 is 15. Now, let's divide that by 40 (the original price) to find the discount. 15/40 is 0.375. Or 37.5% when converted into a percentage. There. Suzanne received a 37.5% discount on the sweater when she bought it.
9. So the car was bought for x dollars. 0.88 represents 88%, so the value of the car is 88% of the previous year. An expression that is a way to describe the change in car value is x * (100 - 0.12)^t, because you car loses 12% of the remaining value each year, which leaves 88% of it remaining, and having the t as the exponent represents the number of years. That expression helps find the value of the car currently and can help you compare the values.
(-4)^2-4(1)(5)
16-4(1)(5)
16-4(5)
16-20
-4
The discriminant is negative so there are no real number solutions.
Turning points are inflection points
think
1st degree (linear) has no turning/inflecion points
2nd degree (quadratic, parabola) has 1 turning/inflection point
so
nth degree has n-1 turning/inflection point
this is 11th degree since highest power is 12
12-1=11
11 turning oints
The two plans cost the same at 450miles.
The cost is $118.50 when the two plans cost the same.
Working is in the photo.
Answer:
- x = ±√3, and they are actual solutions
- x = 3, but it is an extraneous solution
Step-by-step explanation:
The method often recommended for solving an equation of this sort is to multiply by the product of the denominators, then solve the resulting polynomial equation. When you do that, you get ...
... x^2(6x -18) = (2x -6)(9)
... 6x^2(x -3) -18(x -3) = 0
...6(x -3)(x^2 -3) = 0
... x = 3, x = ±√3
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Alternatively, you can subtract the right side of the equation and collect terms to get ...
... x^2/(2(x -3)) - 9/(6(x -3)) = 0
... (1/2)(x^2 -3)/(x -3) = 0
Here, the solution will be values of x that make the numerator zero:
... x = ±√3
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So, the actual solutions are x = ±3, and x = 3 is an extraneous solution. The value x=3 is actually excluded from the domain of the original equation, because the equation is undefined at that point.
_____
<em>Comment on the graph</em>
For the graph, we have rewritten the equation so it is of the form f(x)=0. The graphing program is able to highlight zero crossings, so this is a convenient form. When the equation is multiplied as described above, the resulting cubic has an extra zero-crossing at x=3 (blue curve). This is the extraneous solution.