Which of these systems of equations has a solution of (6,-7) ?

A

x-2y=20

2x-y=19

B

x-2y=20

2x+y=19

C

x+2y=20

2x-y=19

D

x+2y=20

2x+y=19

Silver scooter finds that it costs $300 to produce each scooter and the fixed costs are $750. The price is given by p=900-x, where p is the price in dollars at which exactly x scooters will be sold.

A tennis player hits a serve that cannot be returned 45 percent of the time. Out of 300 serves, how many can yiu predict will not be returned?

To qualify for the championship, a runner must complete the race in less than 40 minutes. Use t to represent the time (in minutes) of a runner who qualifies for the championship.

X=3 5x+4y=-9 -x+4y-2z=-25

Solve for x 6-12x = - 54

Find the range of the function f (x) = 10-x squared

What is ctg of pi? in numbers what it represents?

A+b=0 ab=-36 what is the value of a-b?

A bag of marbles contains 4 green marbles, 3 blue marbles, 2 red marbles, and 5 yellow marbles. How many possible outcomes are there when choosing a marble from the bag

Last month, Korey's Comics had a gross profit of $2,385 with a monthly revenue of $3,465. Korey expects similar sales this month, but he would like to build up his in-store browsing selection, and purchases an additional assortment of comic books