Answer:
x + 2y = -4
Explanation:
A system of linear equations has one solution when the graphs intersect at one point.
Rewrite y = (1/2)x + 2 into the same format as the possible solutions and compare:
y = (1/2)x + 2
multiply both sides by 2: 2y = x + 4
Subtract 2y from both sides: 0 = x - 2y + 4
Subtract -4 from both sides: -4 = x - 2y
⇒ x - 2y = -4
Compare:
- 2x - 4y = 4 ⇒ parallel
- x + 2y = -4 ⇒ intersects at one point
- x - 2y = -4 ⇒ equivalent
- x - 2y = 4 ⇒ parallel