-16 = 8x/5......8x/5 is the same as 8/5(x)
-16 = (8/5)x...divide both sides by 8/5
-16 / (8/5) = x
-16 * 5/8 = x
-80/8 = x
-10 = x <===
40/16 = 24/x
16*24 = 384
x = 384 / 40
x =9.6
it cast a shadow 9.6 feet long
(35 + 47 + 42 + x) / 4 = 50
(124 + x) / 4 = 50....multiply both sides by 4, cancelling the 4 on the left side.
124 + x = 50 * 4
124 + x = 200
x = 200 - 124
x = 76 <===
Thirty two point eight seven five