First of all, let's get rid of the parenthesis at the right hand side:
[tex] -2g+15 = 10+4g-1 [/tex]
Move all terms involving the variable of the left, and all constant terms on the right:
[tex] -2g-4g = 10-1-15 [/tex]
Sum like terms:
[tex] -6g = -6 [/tex]
divide both sides by -6:
[tex] g = 1 [/tex]
