cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Showing results for 
Search instead for 
Did you mean: 

another word problem

another word problem

Please help with another word problem. Please explain in steps.

If a number is multiplied by 7 and this product is increased by 7, the result is 1 less than 9 times. What is the number?

Having the hardest time with word problems. I tried to check my work and it just doesn't come out.
thanks
1 REPLY 1

another word problem

>If a number is multiplied by 7
>and this product is increased
>by 7, the result is 1 less
>than 9 times. What is the
>number?

Start by writing what you know from the problem.

n = the number

A number is multiplied by 7
7n

This product is increased by 7

7n + 7

the result

7n + 7 =

is one less than 9 times (the number)

9n - 1


7n + 7 = 9n - 1

Now try and isolate the n on one side and the numbers on the other.

Subtract 7n from each side

7n + 7 - 7n = 9n - 1 - 7n

7 = 2n - 1

Now add 1 to both sides

7 + 1 = 2n - 1 + 1

8 = 2n

Now divide both sides by 2

8/2 = 2n/2

4 = n

Now substitute the answer back in your original problem to check.

7n + 7 = 9n - 1
7(4) + 7 = 9(4) -1

28 + 7 = 36 - 1

35 = 35 Correct!

Mona


Announcements
Check out the latest
Mathcad Tip
"PTC Mathcad 15 / Prime 1-6 Update."