Can someone good at math figure out these problems then tell me how you got it?

Question

1. If x + 4= -2, the numerical value of -3x - 2 is A. -20 B. 16 C. 4 D. -8

2. If a= -2 and b= 5, what is the value of b - 13/a? A. -4 B. -9 C. 9 D. 4

3. What is 8* 10 to the -2 power in standard notation? A. 0.008 B. 0.08 C. 0.8 D. 800

Answer 1

Sure can..
1) Move the 4 to the right side, so you can isolate x. You do this by subtracting 4 from both sides. x= -2 - 4 Therefore, x = -6. Now you need to figure out what -3(-6) - 2 is..It is simple math. -3 x -6 is 18.. now subtract 2..you get 16
So your answer is b!

2) Just substitute and see:
(5-13)/ -2

Now, 5-13 is negative 8. Now divide -8 by -2. You get +4. Your answer therefore is D

3) Anything to a negative exponent, means put it in the denominator of a fraction. Therefore 10^ -2 means:
1/ (10^2) So.. in this problem just do:

8 x 1/ (10 ^2)
This is 8/100, or B, 0.08

Hope I helped!

Answer 2

Problem 1 Rearrange terms to isolate x by subtracting 4. This gets you x = -6. Now substitute -6 in the equation -3(-6) -2 = 16.

Problem 2 Substitute the values into the problem. 5-(13/-2) = 11.5. So none of the above. However, if the problem should have been (b-13)/a, then the answer is (5-13)/-2 = 4. Remember, a negative/negative -8/-2 = a positive

Problem 3 = 8*10^-2= B. 08. Start by taking 10^-2 = .01 then *8. 10^-2 is taking the reciprocal or (1/(10^2) or (1/(10*10))

Answer 3

First calculate the value of x in the first problem.
x+4=-2
subtract 4 from each side of the = sign
x+4-4=-2-4
x= -6
then input that into the other equation

-3 x -6 = a postive 18

18-2 = 16 the answer is b

The question for 2 needs to be doublechecked.
5 - 6.5 is none of those choices

The question in 3 is pretty cool. Negative notation is the oppositte of powers. 10 to the 2 power would be 100, but 10 to the -2 power would be .1 x 8 = .8. You just move the decimal point the other way for 10's instead of adding 0's.

Answer 4

1 x+4 = -2
x = -6 (subtract 4 from both sides )
-3x-2 = -3*-6 -2 = 18-2 = 16
answer B 16

2. 5 - 13/-2 = 5 + 61/2 = 11 1/2 oops no answer correct
(5-13)/-2 = -8/-2 = 4 answer D

3. 10 ^ -2 is 1/100 or 0.01 so 8 times that is B 0.08

Answer 5

1. x+4= -2 (move the 4 over to the other side)
x= -2-4
x= -6

so then you plug it in the other equation

-3x-2
-3(-6)-2 which equals 18-2

since 3 times 6 is 18 and a negative and a negative is a positive.

which makes the answer B. 16

#2 take one step at a time

5-13= -8

so then it becomes -8/ -2 since a= -2

then answer then becomes D.4

#3. In scientic notation a negative means that you are going to make the number you have smaller...

so then 8 is really 8.0..so you are going to move the decimal place 2 to the left making it .08 which is B. 0.08

Hope that i was able to help...Good Luck!

Answer 6

1) x= -6 Therefore -3(x) = +18
So (-6)+4+2 and (-3) times (-6) is (+18)
So 18-2=16 The answer is B.

2) a=(-2) and b= 5
5 minus 13 divided by -2= ?
5-13= (-8)
-8 divided by -2 = 4
The answer is D.
The 2 negatives cancel out,so it's positive.

Number 3....I have no clue...sorry....

Answer 7

Easy. Just remove anything that isn't a number. So, #1 would be:

4-2-3-2 = -3

Answer 8

1. b because x+4= -2 then x=-6 so -3*-6=18 subtract 2 =16
2. i got -1.5 by dividing -13/-2 then 5 minus 6.5
3. b because 8.*10^-2
ex: 8=8.
move the decimal 2 spots to the left!!!!!


your welcome

Answer 9

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Answer 10

3. is B because 10 to the -2 is 0.01 and 0.01*8 makes 0.08