Exercise 78 Page 180

The first step in simplifying this expression is to identify which, if any, terms can be combined. Remember, only like terms — constant terms or terms with the same variable and the same exponent — can be combined. x + 4x - 3 + 3x^2 - 2x In this case, we have three x-terms, one constant, and one x^2-term. Only the x-terms can be combined, so let's use the Commutative Property of Addition to rearrange the equation and combine like terms.

Let's start by determining which terms can be combined! 2x + 4y^2 - 6y^2 - 9 - x + 3x In this case, we have three x-terms, two y^2-terms, and one constant. Notice that we can combine both the x-terms and y^2-terms. Let's do it!

We want to simplify the given expression. Let's start by identifying the like terms in the expression! 20 + 3xy - 4xy + y^2 + 10 - y^2 In this case, we have two constant terms, two xy-terms, and two y^2-terms. Let's combine the like terms using the Commutative Property of Addition!

We want to evaluate the simplified expressions from Part A and Part B when x= 5 and y= -2. We will evaluate one expression at a time.

Expression A

Let's consider the simplified expression from Part A! 3(x^2+x-1) To evaluate the given expression for x= 5, we will substitute 5 for x in the expression and simplify as much as possible.

The expression is equal to 87 when x= 5.

Expression A

Now we will take a look at the simplified expression from Part B. - 2y^2+4x-9 We can evaluate the given expression for x= 5 and y= -2 by substituting these values into the expression and simplifying it as much as possible. Let's do it!

The expression is equal to 3 when x= 5 and y= - 2.