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+3x, for x=8

Accepted Answer

Welcome back. I'm so glad you're here. We've got an expression alright this bigger. We've got two X squared plus three Y. And then we're given values for our variables were given X equals negative one and Y equals two. Well what does that mean? That means anywhere in our expression we see an X. Here's one. We get to replace that with a negative one. And anywhere in our expression where we see a Y. Here's one. We'll replace that with two. So let's go ahead and do that instead of two X squared. Now it's two times negative one which is still squared plus three and it's no longer three times why it is now three times two. Now that we've got all numbers here we can recall from previous lessons we've got an order of operations given to us by this acronym Pem does that tells us what order to do our addition and so on. Are different operations. So P stands for parentheses Do we have any parentheses here? We do. But those parentheses just have a number inside. They don't have any operations going on inside of them. They're just squished up against another number and that indicates that they are showing multiplication. So we don't have any parentheses to do for our order of operations. Next exponents? Yes we do have exponents. That negative one squared. So that negative one squared tells us we've got negative one times negative one. Those two negatives cancel out. And so now it's just two times one negative one times negative one is positive, one will bring down that plus three times two. No more exponents. And now we can do multiplication and division. Working from left to right. Well we start right off with some multiplication two times one. Well that is two plus and now we've got more multiplication three times to well that is six and no there's no more multiplication or division and we just look for addition or subtraction. While there's only one operation it's addition to plus six that equals eight. We've completed our order of operations and that matches with answer choice D. While done we'll catch you on the next one.

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