1/x=1/400+1/266.67 find the value of x

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

2x minus y equals 6, x plus y equals negative 3

Caleb and emily are standing 100 yards from each other. caleb looks up at a 45° angle to see a hot air balloon. emily looks up at a 60° angle to see the same hot air balloon. approximately how far is the hot air balloon off the ground? a)44.2 yd. b)63.4 yd. c)73.2 yd. d)89.7 yd.