Question

2(r+9)=4(r+4)
Find "r"
Don't goof I actually need the explanation.

Answer 1

Answer:

2r+18=4r+16

2r-4r=16-18

-2r= -2

r= -2/-2

r= 1

Answer 2

Answer: r = 1

Step-by-step explanation: To find r, we must simplify the equation until we have r on one side and a number on the other side.

To keep the equation balanced we must edit both sides evenly.

2(r + 9) = 4(r + 4)

divide by 2:  r + 9 = 2(r + 4)

divide by 2:  r/2 + 4.5 = r + 4

-4:  r/2 + 1/2 = r

times by 2:  r + 1 = 2r

-r:  1 = r

The answer therefore must be r = 1

Another technique to do this would be this, it is quicker but you have to be slightly better at math to do it.

2(r + 9) = 4(r + 4)

get rid of the parenthesis:  2r + 18 = 4r + 16

-16:  2r + 2 = 4r

-2r:  2 = 2r

divide by 2:  1 = r

We get the same answer.

Hope this helps.