Question

Solve the system of linear equations using the matrix method.

What do X and Y equal?

Answer 1

The matrix method is basically making the matrix in the picture equal to

{1 0 = x}

{0 1 = y}

To do this you must multiply reciprocals and add opposites to make 2x = 1, 7y = 0, 3x = 0, and -12y = 1.

I used the simple way of solving linear equations:

3(2x + 7y = 48)

-2(3x - 12y = 27)

6x + 21y = 144

-6x + 24y = -42

45y/45 = 102/45

y = 34/15 or 2.26667

Plug in y-value to get x-value:

2x + 7(34/15) = 48

- 7(34/15) -7(34/15)

2x = 482/15

2x/2 = 482/15/2

x = 241/15 or 16.06667

Answer 2

Algebra - Basic Definitions

A Variable is a symbol for a number we don't know yet. It is usually a letter like x or y. A number on its own is called a Constant.