Question 818715
Solve the second equation for t:
y = 2t + 5
y - 5 = 2t
{{{(y-5)/2 = t}}}
Substitute this expression for t into the first equation:
{{{x = 4((y-5)/2)^2-6}}}
Simplify...
{{{x = 4((y-5)^2/2^2)-6}}}
{{{x = 4((y-5)^2/4)-6}}}
The 4's cancel:
{{{x = (y-5)^2-6}}}
This may be an acceptable form. Or we could square the y-5:
{{{x = y^2-10y+25-6}}}
{{{x = y^2-10y+19}}}