System of linear equations in three variables

Question

y=ax^2 +bx+c (2,3), (-2, 7), (1, -2)

Answer 1

I will not solve this for you, but I will tell you how to do it.

Substitute each of the 3 values of x into the quadratic.

When you set each such expression = to the corresponding ordinate (y value),

you will get a set of 3 linear equations in the unknowns a, b and c

You will immediately be able to eliminate c from the 3 equations, giving you a pair of linear equations in a and b. While potentially messy, the solution for a and b is direct.