Question

How do you solve `(3x - 7) - 5( x - 4) = 21`?

Answer 1

x=-4

Explanation:

[0] `(3x-7)-5(x-4)=21`
First let's simplify by a product rule the term `5(x-4)`
[1] `(3x-7)-5*x-(5*-4)=21`
We also have `-a*-b=a*b`, so:
[2] `(3x-7)-5x+20=21`
Parenthesis on `(3x+7)` are useless, so we have :
[3] `3x-7-5x+20=21`
Let's put all numbers on the right part:
[4]`3x-7+7-5x+20-20=21+7-20`
[5]`-2x=8`
Finally let's Just divide by-2
[6]`x=-4`

Answer 2

`x=-4`

Explanation:

We can start by distributing the `-5` to the `(x-4)` term. We get:

`3x-7-5x+20=21`

We can combine like terms to get:

`-2x+13=21`

We can subtract `13` from both sides to get:

`-2x=8`

Lastly, we can divide both sides by `-2` to get:

`x=-4`

Hope this helps!