Substitute x = -2y + 300 into 3y = 800 - 4x
3y = 8y - 400
Solve for y in 3y = 8y - 400
y = 80
Substitute y = 80 into x = -2y + 300
x = 140
Therefore,
x = 140
y = 80
Answer: D. The equation pair has exactly 2 solutions
Answer:
C) The equation pair has exactly 1 solution.
Step-by-step explanation:
Rewrite the pair of equations
x + 2y = 300
4x + 3y = 800
Multiply the first equation by 4.
4x + 8y = 1200
4x + 3y = 800
Subtract the second equation from the first: 5y = 400 → y = 80 
Putting this value back in the original equation, x = -160 + 300 = 140
The equation pair has exactly 1 solution, x = 140, y = 80