If I'm understanding this correctly:
Tiger consumes 18lb/day of food. If we want to calculate how much is consumed in 28 days, assuming that rate is consistent, the answer is 18*28 = 504lb of food.
Pi is defined as the ratio of the circumference of any circle to its diameter. As all circles are similar and therefore proportional in dimensions, pi is therefore always the same for all circles and is constant
X + x + 165 = 1315
2x + 165 = 1315
subtract 165 from both sides
2x = 1150
divide both sides by 2
x = 575
January 575
February 575 + 165 = 740
Ignore the decimal places and do 789x38 and you get 29982. Now all you have to do is put the decimal places back. Since 789 was 7.89 it had 2 decimal places and 38 had 1 you have to move 29982 three decimal places to the left making your final answer 29.982.
Simplify both sides then isolate the variable
t=10