Good evening ,
Answer :
A.
x = ±20
Step-by-step explanation:
x² − 1 = 399 ⇔ x²= 400 ⇌ x² = 20² ⇌ x² − 20² = 0 ⇌ (x-20)(x+20) = 0
⇌ x = 20 or x = -20.
:)
Answer:
2435
Step-by-step explanation:
add your numbers
Distance traveled by an airplane in 7 hours = 4,914 kilometers
We have to determine the unit rate for kilometers per hour.
So, distance traveled by an airplane in 1 hour = 
= 702 kilometers.
So, an airplane will travel 702 kilometers in an hour.
Therefore, the unit rate for kilometers per hour is 702 km per hour.
0.75 is the decimal format.