QUESTION: Please help! This is a question on my math homework- No calculators allowed:
Work out the value of 5t^2 - 7 when t =4.
When t = 4, t^2 = 4^2 = 4*4 = 16.
Now replace t^2 in the original expression by 16.
5*16 - 7 --- multiply out to get,
80 - 7 -- now do a bit if arithmetic to get,
73