Answer:
x = 1 and x = -1
Explanation:
Next time, please separate the equations with a comma or semicolon. Thanks.
We can substitute 4x for y in the quadratic equation x^2 + y^2=17:
x² + (4x)²=17.
Then x² + 16x² = 17, or
17x² = 17, or x² = 1. There are two solutions: x = 1 and x = -1.