Explain how you can tell wether the graph of a quadratic function opens up or down

If the function is already in the form of y = ax²+bx+c, then all you have to do is look at "a". If it "a" is positive, then it will open up(look like a U) if "a" is negative, then it will open down(look like an upside down U)

A)26•2=52there are 2 sides with the same length116-52=64the other 2 side have to be half of 64 each64/2=32the width is 32b)make two sentences about these steps because your teacher knows how you write and explain things.