Answer
9$a^{2}$ -4 $b^{2}$ + 22
Work Step by Step
( 7 $a^{2}$ -3$b^{2}$ + 10 ) - ( -2$a^{2}$ + $b^{2}$ -12 )
7 $a^{2}$ -3$b^{2}$ + 10 +2$a^{2}$ - $b^{2}$ +12
7 $a^{2}$ +2$a^{2}$ -3$b^{2}$- $b^{2}$ + 10 + 12
combine like terms
9$a^{2}$ -4 $b^{2}$ + 22 simplify