4.2(3.9r – 5.9s) + 7.9s – 9.53r a. 16.88r + 6.85s b. 10.82r + 31.15s c. 10.82r – 31.15s d. 6.85r – 16.88s

  D.  6.85r – 16.88s

Step-by-step explanation:

Use the distributive property to eliminate parentheses, then collect terms.

  4.2(3.9r -5.9s) +7.9s -9.53r

  = 16.38r -24.78s +7.9s -9.53r

  = (16.38 -9.53)r +(-24.78 +7.9)s

  = 6.85r -16.88s

about 80 feet per second

At 55 mph, your vehicle is traveling at about 80 feet per second. Feet-per-second is determined by multiplying speed in miles-per-hour by 1.47 (55 mph x 1.47 = 80 feet per second.)

Step-by-step explanation: