Question

i need help in solving this math question(-2z2-14)-(-12z2)

Answer 1

$(-2z^2-14)-(-12z^2) =$

Remove parentheses:

$-2z^2 - 14 + 12 z^2$

Group like  terms :

$-2z^2 + 12z^2-14$

add similar elements: 

$-2z^2+12z^2 = 10z^2$

$=10z^2-14$

hope this helps!