Step-by-step explanation:
2(x+10)=60
x+10=60/2
x=30-10=20
Answer:
9000 ft
Step-by-step explanation:
Given: A airplane is ascending at a constant rate of 15 feet per second,
What we need to know: The change in altitude during 10 minutes of flight,
60 seconds = 1 minute
60 × 10
= 600 seconds
600 × 15
= 9000 ft
Therefore there was a 9000 ft change in altitude during the 10 minutes of the flight.
It is understood without being written that the slope of this line is 1. If we rewrite the point-slope form of the line it would be y-8=1(x-4) where 1 is the slope. We move the -8 over by addition to get y = 1x-4+8, or, simplified, y=x+4, the first choice in your answers.