CHAPTER 1 REVIEW

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1.4 REWRITING EQUATIONS AND FORMULAS

7x -3y = 8 -7x___________________

-3y = -7x + 8

-3y = -7x + 8 -3 -3 -

3_________

y = x -

First, we need to get rid of the 7x. To do this we will subtract it from both sides of the equal sign.

_______________________________________

Now because you cant take 7x away from 8, it just rests as a negative. -7x, having a variable, goes before the number 8.

________________________________________Now to get “y” by itself, we need to

divide everything by -3, on both sides of the equal sign.

________________________________________

Congrats! You’ve completed the equation!

Example 1: Rewriting an Equations With More Than One Variable.

Step by step procedure

1.4 REWRITING EQUATIONS AND

FORMULAS

x + xy = 1__________________

x + xy = 1 -x -x__________________

xy = 1 – x__________________

xy = 1- x x x_________________

_____________________

In this equation, we will find the value of y when X= -1 and 3. so anytime we solve for y, we need to isolate it.

______________________________________

In order to isolate the y, we need to subtract x from each side of the equal sign.

_______________________________________ Just like in the last example, you cannot take

a number from a variable, so it rests as a negative before the x on the right side of the equal sign.

_________________________________________Now we divide both sides by x. _________________________________________ Substitute x for the given value and Voila!

You’ve just solved the problem!

Example 2: Calculating the value of a variable Step by step procedure

1.4 REWRITING EQUATIONS AND FORMULAS

The school is having their annual spring musical, if there are only two types of ticket, adult and child, write an equation with more than one variable that represents the revenue from opening night.

_____________________________ We need the amount of people vs.

the price of tickets in order to see the revenue of the show, so r would equal the prices times the amount of people.

_____________________________

Congrats! You’ve solved the problem!

Example 3: writing an equation with more than one variable Step by step procedure