Jeri has a total of 40 pets with a total of 160 legs. If she owns only cats and dogs, how many of each does
she have? Write a system of equations to represent
this situation. Solve it using any method.

let x be the number of cats and y be the number of dogs:

x + y = 40

4x + 4y = 160

If you divide both sides of the second equation by 4, you will be left with:

x + y = 40

Then, subtract both equations:

x + y =40

- (x + y = 40)

0 = 0

Since you have a number = a number, there are infinite solutions.

hello from mrbilldoesmath!

answer:

the domain is the set { -2, 0, 2, 3}

discussion:

the domain is the set of x values in the ordered pairs (x,y). taking the x, or first component, of each ordered pair gives   -2, 0, 2, 3.

you,

mrb

9x