Mathematics

# Subtract a^2 - 7a + 11 from the sum of 3a^2 - 4 and 5a^2 + 6a

$3a^2-4+5a^2+6a-(a^2-7a+11)=\\ 8a^2+6a-4-a^2+7a-11=\\ 7a^2+13a-15$