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). 7+5x, for x = 10

Accepted Answer

Welcome back. I'm so glad you're here. We are given an expression. I'll write it bigger. Two plus three X. And we are given a value for our variable X. X equals negative one. What does this mean means that anywhere we see an X. In our expression here's one. We're going to replace that X. With negative one. So let's go ahead and do that. We bring down the two and the plus and the three and the three is no longer times X. It is now times negative one. Well great. We've just got numbers here so we can evaluate this expression and we're going to do so by recalling from previous lessons this acronym Pen does which gives us a clue about the order of operations. So that P and Penda stands for parentheses. We're going to do anything with parentheses first. Do we have any parentheses? Well there are parentheses there around that negative one. But there aren't any operations happening within the parentheses. And when we see a parentheses with a number of variable inside and it's squished up against another number variable. That means those parentheses actually indicate multiplication. So for the sake of Pandas, we're not talking about parentheses here. Those parentheses indicate multiplication. Are there any e exponents happening here? Nope. No exponents. We can check that one off next. In Pem does M and D tell us that. Working from left to right. If we see any multiplication or division. We're going to do those in order from left to right. Is there any multiplication or division. Well yeah, what we said before about that three being multiplied by the negative one. So we can go ahead and do that. Bring down the two plus and three times negative one. Well that's negative three. And we recall from previous lessons that this is the same thing two plus negative three is the same thing as two minus three. So is there any other multiplication or division happening here? Nope. It's just two minus three. Which is one operation. That last operation is subtraction. So the and the S. Stand for addition and subtraction. Working from left right, we've only got subtraction. So let's do that two minus three equals negative one. We look at our answer choices and that matches with answer choice. B. Well done, we'll catch you on the next one.

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