Answer:
x=-3
Step-by-step explanation:

x+3=0
-3 -3
x= -3
opposite of addition would be subtraction. since your trying to solve for x You want to get x alone and you subtract by 3 on both sides which would cancel the 3 on the left, leaving:

if you follow the same process on all of them you come to the conclusion that only -3 is a zero in the options listed.
NOTE: When you become more experienced whenever you see expressions like that you'll come to realize that the zero is the opposite sign of the number if it's just x- or x+ a number.
example:

it'll be the opposite sign so since it's a negative the zero of that would be positive 40.
hope this helps!
Answer:
6
Step-by-step explanation:
( 8 + 13 )
if you add them all together then divide thats u answer !
First we need to know how many miles per hour they drove the first time. This would be found by division. 168/3.5=48
Then we need to add 5 miles per hour for the average.48+5= 53
Next we need to multiply 2 1/4 by the new miles per hour 53*2.25=119.25
After that we need to know how many miles they drove 119.25+168=287.25 miles.
Finally to get an improper fraction we need to change 287.25 miles to it.
We already have 1/4 for .25 so we multiply 287 by 4 and add it to the 1/4 we already have and it makes it out to be 1149/4
Hope this helps!
Answer:
it is 8 if i substitute x for 3
Step-by-step explanation: