Just multiply and simplify that is your best bet
Answer:
Step-by-step explanation:
add up their speed.
combined speed = x+ 1 x + 10
( 2 x + 10 )
Time = 5 hours
Distance = 750 miles
Distance = speed * time
( 2 x 10 )* 5 = 750
10 x + 50 = 750
10 x = 750 + -50
10 x = 700
/ 10
x= 70 mph Car A
Car B 70 + 10 = 80 mph
A set has closure under an operation if performance of that operation on members of the set always produces a member of the same set; in this case we also say that the set is closed under the operation.
A closure property is a certain rule that holds <u>if it is true for all elements of a set under the given operation</u> and a closure property does not hold <u>if there is at least one pair of elements that do not follow the closure property under the given operation.</u>
Therefore, Emma is correct, because you can find a counterexample (7:2=3.5) that gives you a non-integer answer.
Answer: correct option is B