PLEASE HELP If x+y−z=8 and x−y+z=12, then x=

(C) 10

Step-by-step explanation:

x+y−z=8

Subtract y from both sides

x-z= -y+8

Add z to both sides

x= -y+z+8

Subtract 8 from both sides

x-8= -y+z

x−y+z=12

Add y to both sides

x+z=12+y

Subtract z from both sides

x=y-z+12

Subtract 12 from both sides

x-12=y-z

Multiply both sides by -1

-x+12= -y+z

Combine equations:

x-8= -x+12

Add x to both sides

2x-8+12

Add 8 to both sides

2x=20

Divide both sides by 2

x=10

The answer is (C) 10.

47 - 90 = 43

43 - 180 = x

x = 137