Solve :
The curve passes through the points $$(-10 , -150)$$ and $$ (k , -150)$$.
Use the symmetry of the curve to find the value of $$k$$.
The curve is passing through point $$\left( -10,-150 \right) $$
Thus, its symmetrical curve must pass through point $$\left( 10,-150 \right) $$
Thus, $$k=10$$