Quicksuppose a particle is moving along the x-axis. the position, measured in feet, of the particle can be modeled by the quadratic equation y = 3x2 − 12x − 9, where x is time, in seconds. what does the number −9 represent for the quadratic function?   the particle is 9 feet to the left of the origin. the particle is moving left 9 feet per second. the particle is accelerating at −9 feet per second squared. the particle has stopped at 9 seconds.

Sam opened a money-market account that pays 3% simple interest. he started the account with $7,000 and made no further deposits. when he closed the account, he had earned $420 in interest. how long did he keep his account open?

At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. the cyclic nature of wind and moving sand determines the shape and location of large dunes. at a test site, the prevailing direction of the wind did not change noticeably. however, the velocity did change. fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. based on long-term experience, σ can be assumed to be 245 cm/sec. (a) find a 95% confidence interval for the population mean wind speed at this site. (round your answers to the nearest whole number.) lower limit cm/sec upper limit cm/sec

Solve for x -3+3b> 9a: ) x> 4b-9/3b: ) x< 9-4b/3c: ) x< -4b+9/-3d: ) x> 4b+9/-3