As part of a school contest, Sarah and Luis are playing a math game. Sarah must pick a number between 1 and 50 and give Luis clues so he can write an equation to find her number. Sarah says, "If i subtract 5 from my number, multiply that quantity by 4, and then add 7 to the result, i get 35." What equation can Luis write based on Sarah's clues and what is Sarah;s clues and what is is Sarah's number?