7a-2a-5b+b= ??

I dont understand this can anyone help

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x, y) ?

Which table shows a proportional relationship between miles traveled and gas used?

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