1.7 Reading and Writing Equations

1.7 Reading and Writing Equations

Focus - Translate statements into EQUATIONS

2c + 1 is an ALGEBRAIC EXPRESSION

It reads...One more than twice a number.


2c + 1 = 7 is an EQUATION

It reads…..One more than twice a number is seven.


In an Equation, the variable has only ONE value...only one value makes this equation true.

The only value for c that makes this equation true is "3"
2(3) + 1 = 7
6 + 1 = 7
7 = 7

When writing an equation from a statement, follow these steps:

Eg. A NUMBER SUBTRACTED FROM TEN IS FOUR.

1. Select a variable…..
...Let c = the number.

2. Write an algebraic expression representing the relationship.
...10 - c

3. Write an equal sign between the expression and the constant.
...10 - c = 4

There are 3 parts to an algebraic expression:

Numerical coefficient - N.C.
variable - v
Constant Term - C.T.

when writing an equation we add a 4th part

answer =

To solve a word problem, organize all the information you have into the correct spot:

Ex: THREE MORE THAN SIX TIMES THE NUMBER IS THIRTY-THREE

N.C. - 6 ("6 times")
v - n ("a number")
C.T. - +3 ("3 more")
answer = 33

So, our EQUATION is... 6n + 3 = 33