Letra a=> 12
+2+(-3)+(-2)+5+(10)
+2-3-2+5+10
12

Letra b => 22
+2-(-3)-(-2)-(5)
+2+3+2-5
+7-5
+2

Letra c=> -19
2a+3b-c-5d+e
2×2+(3×-3)-(-2)-(5×5)+10
3+(-9)+2-(25)+10
3-9+2-25+1£
+15-34
-19

Letra d=> +13
-3a-2b+c+d+e
-3×(2)-2×(-3)+(-2)+5+10
-(6)-(-6)-2+15
-6+6-2+15
-2+15
+13

Letra e=>13
-5a+b-3c+2d-e
-(5×2)+(-3)-(3×-2)+(2×5)-10
-(10)-3-(-6)+10-10
10-3+6+10-10
+26-13
13

Letra f =>-16
ab+cd
[2×(-3)]+[(-2)×5]
(-6)+(-10)
-16

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