Answer
$4m^{2}-m+17$
Work Step by Step
$(-m^{2}+3)-(m^{2}-13)+(6m^{2}-m+1)$
Remove all the parentheses. To remove the second one, change the sign of every term inside it:
$-m^{2}+3-m^{2}+13+6m^{2}-m+1=...$
Simplify by combining like terms:
$...=(-1-1+6)m^{2}-m+(3+13+1)=4m^{2}-m+17$
