What is the answer to 3 (x+2 )=2 (x+5)?

the answer is x+4

you have to distribute your 3 & to the x its by   

twenty-six miles over two gallons because the proportion for the original 13 miles to one gallon would be written 13/1 and, doing the same thing to the top and bottom, i multiplied by 2 and got 26/2