Find two numbers whose sum is 1 and whose difference is -9.

-4,5

Step-by-step explanation:

Set up two equations:

1. x+y = 1

2. x-y=-9

Solve it algebraically. You can use elimination or substitution.

Elimination:

 x+y=1

- x-y=-9

    2y=10

       y=5

Now you can substitute:

x+y=1

x+5=1

x=-4

Thus, x=-4 and y=5.

30 feet

step-by-step explanation:

that would be 2 1/2 * 12

= 24 + 6

= 30 feet   (answer)