A small plane flying from Los Angeles to San Diego averaged 175 mph with a tailwind. On the return trip with headwind the average speed was only 125 mph. Write and solve a system to reflect this relationship. Find the speed of the headwind/ tailwind AND the speed of the plane on a calm day.

 System of equations:

p + w = 175

p - w = 125

p is the plane's speed, w is the wind speed

The wind speed is 25 mph.  The plane's speed on a calm day is 150 mph.

Step-by-step explanation:

Solve by elimination: Add the equations. w "cancels" solve for p:

p + w = 175

p - w = 125

2p  = 300   divide both sides by 2

p = 150  the plane's speed

Substitute 150 for p and solve for w

150 + w = 175   Subtract 150 from both sides.

w = 25  the wind speed

8

step-by-step explanation:

$54.99

step-by-step explanation:

$54.99 includes 500 min. if she does not exceed 500 min then her bill is $54.99