Math, How Do I Do These?

[reeses4life]

How do I SOLVE these?
1. Use the function rule f(x)=x* -1 ^x
A) 4
B) 3
C) -2
D) 2

2. 5x3n
A) 15,30,45,60
B) 5,15,45,135
C) 0,15,45,135
D) 15,35,135,405

[Old_Geezer]

1. I suspect you substitute the value given for x in the equation and state the value of the result.

2. Unless there are 4 answers for each of the 4 sub-parts, I'm unsure about this one. Is that the total question ?

[reeses4life]

Yeah that is the full question, what do you mean for the first one?

[Old_Geezer]

No mathematician, so I'm leaving myself wide open to criticism but:

f(x)= x squared, multiplied by, - 1 to the power of x

4 squared = 16, -1 to the forth power is 1, so my thought is that 16 * 1 = 16

But if I were you I'd wait until a maths teacher posts a solution method.

[fiction-factory]

Is the first question exactly as printed?

Q2 doesn't make sense as it's an incomplete question but if you meant to ask what are the first 5 terms of the sequence with nth term rule 5 x 3n (more simply 15n) then yes the answer is A

[Old_Geezer]

Are you suggesting that it is multiple choice ? It looked like 2 blocks of 4 questions to me.

[reeses4life]

Yeah both of those questions are exactly as printed

[fiction-factory]

The first one doesn't make sense either. Were you asked to solve it or asked to work out the value of the function for a given value of x. Or did it say solve it for a given value for the function - eg when f(x)=0

The function seems odd as set out as it is x multiplied by -1 to the power of x. The value of -1^x will alternate between -1 and +1, so the function is effectively alternating between -x and x

[fiction-factory]

You need to check the source. These are not questions.
The first is like saying solve 3x+2. There is no answer. You need an equality in there- eg solve 3x+2=0.

The second one is incomplete too for the reason i gave earlier. There is no question- just an expression and a choice of answers. The answer is almost certainly A but i would point out the poor quality of the question to your teacher

[fiction-factory]

reeses4life has now corrected question 1 on a new thread. The question now asks for f92) so teh answer is 2 x (-1)²= 2 x 1 = 2