Question

2g+7=-4g+7+6g how do you solve that

Answer 1

$2g+7=-4g+7+6g \\\\\\ 2g+7=2g+7 \to True \ statement \\\\\\ 2g-2g=7-7 \\\\ \boxed{0=0}$

Answer 2

You can move all the terms with g in left, and the free terms in right. 
2g+7=-4g+7+6g
2g+4g-6g=7-7
0=0 => It's true.