2.4 12. Use tiles or a number line to subtract. Write the subtraction equations.
a) $(+4)-(+1)$
b) $(+5)-(-1)$
c) $(+2)-(-2)$
d) $(-4)-(+1)$
e) $(-6)-(-2)$
f) $(-10)-(-5)$
g) $(-4)-(-2)$
h) $(-5)-(-10)$
13. Subtract.
a) $(+7)-(+2)$
b) $(-7)-(+3)$
c) $(-4)-(-5)$
d) $(+3)-(+3)$

Step 1 ：\( (+4)-(+1) = \boxed{3} \)

Step 2 ：\( (+5)-(-1) = \boxed{6} \)

Step 3 ：\( (+2)-(-2) = \boxed{4} \)

Step 4 ：\( (-4)-(+1) = \boxed{-5} \)

Step 5 ：\( (-6)-(-2) = \boxed{-4} \)

Step 6 ：\( (-10)-(-5) = \boxed{-5} \)

Step 7 ：\( (-4)-(-2) = \boxed{-2} \)

Step 8 ：\( (-5)-(-10) = \boxed{5} \)

Step 9 ：\( (+7)-(+2) = \boxed{5} \)

Step 10 ：\( (-7)-(+3) = \boxed{-10} \)

Step 11 ：\( (-4)-(-5) = \boxed{1} \)

Step 12 ：\( (+3)-(+3) = \boxed{0} \)