What is breaking apart to find a math answer mean?

Find the sum and express it in simplest form. (3t2 + 6t + 1) + (-9t2 - 5t)

1.-There were 70 000 spectators at a football match. 42 000 of them supported Manchester United. What fraction of the spectators supported Manchester United? (Fraction in the simplest form) 2.

Given that a new fuel-efficient cars can drive 55 miles per gallon, how far can a car drive with nine gallons? 6.11 miles 455 miles 495 miles 540 miles

I don't know how to do this

Round 3, 942,588 to the nearest thousand

Select the statement that correctly describes the expression below (5x - 3) ^2

find the absolute error and percentage error in rounding; the yearly profit of $1367540 made by a company to $1.37 million

How many atoms are in 2.50 moles of iron

Zoe's pizza cost $12.99. She gave a tip of $2.00. What percent did Zoe leave as a tip?

Y=3x+5 + what is the answer