Subtract 5 from the sum of

x and 7 times 3 and the result is 20.

My answer is

x-5 + 7 x 3 = 20

x = 4 is that right?

Printable View

- Feb 28th 2007, 09:36 PMPatienceWriting an algebraic equation
Subtract 5 from the sum of

x and 7 times 3 and the result is 20.

My answer is

x-5 + 7 x 3 = 20

x = 4 is that right? - Feb 28th 2007, 09:47 PMJhevon
- Feb 28th 2007, 09:49 PMearboth
Hi,

your calculations are OK, but for me the following way is possible too:

First calculate the sum: (x+7)

The sum should be multiplicated by 3: (x+7)*3

Subtract 5 from this product: (x+7)*3 - 5

The result is 20:

3*(x+7) - 5 = 20 Expand the bracket:

3x + 21 - 5 = 20 Collect all constants at the RHS of the equation:

3x = 20 - 21 + 5 = 4 Divide both sides by 3:

x = 4/3

EB - Feb 28th 2007, 10:02 PMPatience
Yes that is the exact question.

After looking at your calculation I am kinda lost.

You say that x = 4/3

How do you solve 4/3 to = 20? - Mar 1st 2007, 04:45 AMJhevon