Answer:
Step-by-step explanation: First, let's call the starting elevation of the plane: e
We can then write an equation representing this problem as:
e−1.5mi=5.25mi
Now, add 1.5mi to each side of the equation to solve for e
while keeping the equation balanced:
e−1.5mi + 1.5mi=5.25mi + 1.5mi
e−0=6.75mi
e=6.75mi
The plane's starting elevation was 6.75 miles
