Evaluate the expression if a=-2 and b = 5

Tree diagram to find the prime factors of 18

Ican figure out 20 shares multiply by $117.98 =2359.6920 shares multiply by $124.32=2486.40then take 40 shares multiply by $128.48=5139.20after that i'm lost any be greatly appreciated.

He concluded that a heavier object dropped from the same height as a lighter object will land