Math hw, I don't understand how to do it, question attached in picture

Asap will give brainliest and a lot of points

Raj encoded a secret phrase using matrix multiplication. using a = 1, b = 2, c = 3, and so on, he multiplied the clear text code for each letter by the matrix to get a matrix that represents the encoded text. the matrix representing the encoded text is . what is the secret phrase? determine the location of spaces after you decode the text. yummy is the corn the tomato is red the corn is yummy red is the tomato

Over which interval is the graph of f(x) = x2 + 5x + 6 increasing?