5d+4=12 how can i solve for the equation

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days

$5400 is? invested, part of it at 11? % and part of it at 8? %. for a certain? year, the total yield is ? $522.00. how much was invested at each? rate?

Based on the diagram above, a student determined the hypotanuse of the triangle to be 6√3. determine if the students answer is correct. if not correct find the correct length