In Exercises 1–16, evaluate each algebraic expression for the giv...

Question

In Exercises 1–16, evaluate each algebraic expression for the given value or values of the variable(s). x^2-6x+3, for x=7

Accepted Answer

Welcome back. I'm so glad you're here. We've got an expression and I'll rewrite that bigger. We've got y squared plus two y minus two and were given a value for our variable. Why? Why equals three. Well what does that mean? Anywhere? We've got a Y. In our expression here's one here's another. We are going to replace that. Why? With a three? So let's go ahead and do that instead of why squared? It's now three squared plus two and not two times why? It's now two times three minus two. And great. We've got all numbers here. So now if you recall from previous lessons this acronym Pem Da's we are going to use this to recall the order of operations meaning we're going to start with parentheses. Then work with exponents. And then from left to right do multiplication and division and from left to right, do addition and subtraction. So do we have any parentheses? Well we have parentheses around that. Three but there's no operations happening inside those parentheses. So when you have a number squished up against parentheses like that and there's just a number variable inside the parentheses. It means that these parentheses mean multiplication. So actually no we don't have any parentheses here. And do we have any exponents? Yes, we do. We've got three squared. So let's do that. First three squared is nine and bring down the rest plus two times three minus two. Great. Exponents are done multiplication and division while working from left to right. The only multiplication that we have going on here is this two times three. So we can bring down the nine and we've got positive two times positive three. That's going to be plus six and then bring down this minus two. And that step is done. Now all we've got left are addition and subtraction. And it's important to note that those to happen on an equal plane, but working from left to right, so we start on the left and then we say nine plus six, nine plus six is 15 and we can bring down that minus two and now minus two is all that's left and that is 13. So our final step of the order of operations is done. We've got an answer and it matches with answer choice B. While done, we'll catch you on the next one.

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