How do you know that calculating 80% of the regular price gives you the same result as subtracting 20% from the regular price

Y = 5x - 6 Identify the y-intercept of the following equation.

How do I find the domain of f (t) = t^2-6t? (I also need to sketch the graph of the function!)

Each marble bag sold by jenny's marble company contains 3 yellow marbles for every 5 orange marbles. if a bag has 15 yellow marbles, how many orange marbles does it contain?

If Jill has 2 more cats than dogs how many fewer dogs does Jill have

Is the sum 45/100 greater than or less than 1/2? explain

A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporters data is valid or not?

I am very confused on how to figure out if y = 3/4x is proportional?

Alison wants to buy a mountain bike for $339.12. If she saves $28.26 each month, in how many months will she be able to buy the bike?

At 12 o'clock the temperature was 7°C. The temperature decreased by - 20°C. What is the new temperature?

Ashleys rentals charges $27.50 per hour to rent a surfboard and a wetsuit. Darlas surf shop charges $23.25 per hour to rent a surfboard plus $17 extra for a wetsuit.