How do you subtract linear expressions

What is the answer to - 39.75 = 7.5 M

A farmer has a total of 21 cows and chickens altogether The animals have 54 legs how many cows and how many chickens does the farmer have?

What is the 9th term of the sequence which has a first term of 1 and has a common ratio of 1.5?

Find the total surface area of each prism or cylinder. (Base is a Rhombus) * - 10 yd 20 yd 13 yd

Two baseball players hit 68 home runs combined last year. The first player hit 5 more home runs than twice the number of home runs the second player hit. How many home runs did each player hit?

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.