How do I solve this linear equation x+2y=63x-y=4 by graphing , elimination, and substitution. please explain

x = 71/3

y = 59/3

Step-by-step explanation:

You can solve this equation by all three methods.

By substitution:

Rewrite  x - y = 4  to make x the subject:  

x = 4 + y

Substitute  x = 4 + y  into  x + 2y = 63  and solve for y:

⇒ (4 + y) + 2y = 63

⇒ 4 + y + 2y = 63

⇒ 4 + 3y = 63

⇒ 3y = 59

⇒ y = 59/3

Now substitute found value for y into  x - y = 4  and solve for x:

⇒ x - 59/3 = 4

⇒ x = 71/3

By graphing

Graph the two lines.  The solution is the point of intersection:

By elimination

change the signs of  x - y = 4

⇒ - x + y = -4

Now add to  x + 2y = 63  to eliminate x:

⇒ 3y = 59

⇒ y = 59/3

Substitute found value of y into  x - y = 4  and solve for x:

⇒ x - 59/3 = 4

⇒ x = 71/3