PROBLEM
2x - 4y = 20
4x - y = -2
METHOD
Use substitution method
Step 1
name the equations
2x - 4y = 20 ..................................1
4x - y = -2 ....................................2
Step 2
Choose one equation, make one variable subject of relation
from equation 2
4x - y = -2
4x + 2 = y
Step 3
substitute y in equation 1
2x - 4y = 20
2x - 4(4x + 2 ) = 20
2x - 16x - 8 = 20
2x - 16x = 20 + 8
-14x = 28
Divide by -14
x = 28/-14
x = -2
Step 4
substitute x in equation1 to find y
4x + 2 = y
4(-2) + 2 = y
-8 + 2 = y
-6 = y
y = -6
