Question

Can someone please help me and teach me how to do this !!!!

x+y= 11
-x=-y-9

O A. (10,1)
O B. (11,0)
O C. (9,2)
O D. (8, 3)

Answer 1

A. ( 10, 1 )

Explanation:

Isolate x for x + y = 11.

x + y = 11

Subtract y from both sides.

x + y - 11 - y

Simplify.

x = 11 - y

Substitute x = 11 - y

[ - ( 11 - y ) = -y - 9 ]

Isolate y for - ( 11 - y ) = -y - 9.

- ( 11 - y ) = -y - 9

Expand - ( 11 - y )

Add 11 to both sides.

-11 + y + 11 = - y - 9 + 11

Simplify.

y = -y + 2

Add y to both sides.

y + y = -y + 2 + y

Simplify.

2y = 2

Divide both sides by 2.

`(2y)/(2) =(2)/(2)`

Simplify.

y = 1

Substitute y = 1.

x = 11 - 1

Subtract the numbers: 11 - 1

= 10

x = 10

y = 1

( 10, 1 )