Answer: 49
Step-by-step explanation:
A). |x| = |-x|
This is always true.
The definition of 'absolute' value is 'size of the number without its sign'.
That's what this expression says.
b). |x| = -|x|
This is never true, because an absolute value is never negative.
This one would true if x=0 . So maybe some people might say
it's sometimes true, but that doesn't feel right to me. I say never.
c). |-x| = -|x|
This looks to me like exactly the same situation as (b),
and I would say all the same things about it.
Answer:
The last quiz score must be at least an 80 to get the average to be a 70.
Step-by-step explanation:
In order to find this, you need to take the average of the 4 test scores along with the unknown test score (x). So, to find an average, we add all the numbers together and divide by the amount of tests taken. We can then set this equal to 70 since that is the minimum average.
(60 + 64 + 75 + 71 + x)/5 = 70 ------> Multiply both sides by 5
(60 + 64 + 75 + 71 + x) = 350 -----> Combine like terms
270 + x = 350 -----> Subtract 270 from both sides
x = 80
A = 2+3a +6
a-3a = 8
-2a = 8
a = -8/2 = -4
