Answer:
Option A. x² + 9x² = 49
Step-by-step explanation:
Luanne used two equations given as 2y = 6x ------(1)
and x² + y² = 49 -----(2)
Luanne isolated the value of y from the equation 1 and then substituted in equation 2.
We will do the same.
from equation 1
2y = 6x
⇒ y = 3x
Now we plug in the value of y in equation 2.
x² + (3x)² = 49
x² + 9x² = 49
which matches the option A.