.
"equation of a parabola with vertex (2,3)" is
y = a*(x-2)^2 + 3,
where "a" is an unknown coefficient, which should be found.
"passing through (1.5,4)" means
4 = a*(1.5-2)^2 + 3,
which is the same as
4 = a*(-0.5)^2 + 3
4 - 3 = a*0.25
1 = 0.25a
a =
= 4.
So, the final equation of the parabola is y = 4*(x-2)^2 + 3.