156k views
4 votes
7x-5=8(x*3) what value of x makes this equation true

2 Answers

3 votes

Explanation:

Question:-

Solve for x


\\ \tt{:}\leadsto 7x-5=8(x+3)

SOLUTION:-


\\ \tt{:}\leadsto 7x-5=8(x+3)


\\ \tt{:}\leadsto 7x-5=8x+24


\\ \tt{:}\leadsto 7x-8x=24+5


\\ \tt{:}\leadsto -x=29


\\ \tt{:}\leadsto x=29

User NewbieMACuser
by
7.9k points
6 votes

The given equation is:


\displaystyle 7x-5=8(x+3)

The first step you need to do is open the parentheses and distribute the 8 to x+3. It will be 8 times x and 3 times x.


8(x+3)=8 * x+ 8 * 3\\\\8 * x=8x\\8 * 3=24


8(x+3) \rightarrow 8x+24

Rewrite the equation:


7x-5=8x+24

Now you need to move one of the variables to the other side.

If you move 7x to the other side, then:

You can move the variable by doing the opposite of it. Since 7x is positive, you can move it by subtracting 7x, which is negative. Subtract 7x on both sides:


7x-5-7x=8x+24-7x\\-5=x+24

Now you need to leave x alone. x is being added to 24, so remove it by subtracting both sides by 24. Remember that when you're subtracting from a negative number, you're actually adding while keeping the negative sign.


-5-24=x+24-24

Subtract:


\bf-29=x

If you move 8x to the other side, then:

8x is positive, so you can move it by subtracting 8x, which is negative. Subtract 8x on both sides:


7x-5-8x=8x+24-8x\\-x-5=24

You need to leave the variable alone, so move -5 to the other side. You can do this by adding 5 to both sides.


-x-5+5=24+5\\-x=29

Lastly, x is negative, but you're looking for the value of positive x. Divide both sides by -1 to remove the negative sign.


\displaystyle (-x)/(-1) =(29)/(-1)

Remember that a positive number divided by a negative number is negative. Divide:


\bf x=-29

The answer to your question is x = -29.

User Neeraj Verma
by
7.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories