The system of equation given is
7x² + 3y² = 187 (no operation is shown in the problem, it is assumed there is a plus sign)
3y² - 7x = 47
From the first equation
3y² = 187 - 7x²
Substituting
187 - 7x² + 7x = 47
-7x² + 7x 140 = 0
The solution of this equation is
x = -4 and 5
And solving for y
y = 25 and 4