Question

4(x+9)=2x-6
Solve for x

Answer 1

-21

Explanation:

4(x+9) = 4x+36

4x+36 = 2x-6

-36 -36

minus 36 from both sides

4x = 2x-42

2x = -42

-42/2 = -21

x = -21

Answer 2

Hi there!

We are given the equation below:

`\large \boxed{4(x + 9) = 2x - 6}`

1. Expand 4 in the expression.

• When expand in the expression, it is like multiply everything in the expression. So when we expand 4 in x+9, it becomes 4(x)+9(4).

`\large{(4 * x) + (9 * 4) = 2x - 6} \\ \large{(4x) + (36) = 2x - 6}`

Cancel the brackets.

`\large{4x + 36 = 2x - 6}`

2. Isolate x-term and solve for the variable.

• Think it easy. If you want to isolate x-term then what should you do? Well simply swap sides, and change the operator/sign.

`\large{4x - 2x = - 6 - 36}`

Finally, combine like terms.

`\large{2x = - 42}`

Then divide both sides by 2 so we can finally leave only x-term.

`\large{ (2x)/(2) = ( - 42)/(2) } \\ \large \boxed{x = - 21}`

3. Check the solution if it is right or wrong.

• This step is optional but if you are not confident on your answer, this step is recommended.

To check the answer, we simply substitute the value of x which is -21 in the equation and see if both sides are equal or not. If both sides are equal then the answer is correct, if not then the answer is wrong. Therefore,

`\large{4(x + 9) = 2x - 6 \longrightarrow 4( - 21 + 9) = 2 ( - 21) - 6} \\ \large{4( - 12) = - 42 - 6} \\ \large{ - 48 = - 48}`

Since both sides are equal when substitute in x = -21.

4. Answer

• Hence, the answer for this equation is x = -21.

I hope this helps and let me know if you have any doubts!