Answers:
A = 3
B = -7
C = 3
D = -7
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Explanation:
You could use the AC method to factor, but I think the method described below is a more efficient way of factoring.
Set the given expression equal to zero and solve for x using the quadratic formula. So the goal is to find the roots for
We'll plug in a = 9, b = -42, and c = 49.
Because the root is x = 7/3, it leads to the factor 3x-7 = 0
Note that we go from x = 7/3 to 3x = 7 after multiplying both sides by 3. Then we subtract 7 from both sides.
It turns out that we have two copies of the identical factor (3x-7) because x = 7/3 is a double root.
So in reality we have the factorization (3x-7)(3x-7) which we can shorten into (3x-7)^2 if we wanted.
Use the box method or FOIL method to expand (3x-7)(3x-7) and you should get 9x^2-21x-21x+49 which simplifies to 9x^2-42x+49. This confirms we have the correct factorization.
Therefore, A and C are both 3, while B and D are both -7.
I don't understand the question either. The only answer I can think of is possible that the volume would be entered in the unit cubed. By that I mean: 4 in.^3 while surface area I think would just be in.^2 (squared). I'm not 100% sure that is what they are asking but if it is this should be the answer. Hope it helps.
Answer:
5x - 1
Step-by-step explanation:
i don't know hw to explain it but that's the answer
Okay. So the song lasts 221 seconds. 45 seconds have already beem done and 22 seconds is done in an hour. The equation would be set up like this:
45 + 22h = 221
Just by looking at the answer choices, A is already eliminated because it doesn't incorportate the 45 seconds. B does include the 45 seconds, but it subtracts, and in this case, we add time, not subtract. D is eliminated, because the h variable does not go with 45. The only equation that works is C and when you solve it, you get 8 hours. The answer is C.
Note: you solve the equation above by subtract 45 from both sides to get 176 = 22x, and dividing both sides by 22 to get x = 8.