Optellen en aftrekken (reeks 3)

Hoofdmenu Eentje per keer  🖨

Reken uit

1. \(-7-9+1-9+7=\)
2. \(-(+2)-(-8)-(-1)-(-1)+(+7)=\)
3. \(+(-2)+(-6)-(+5)+(-5)-(+7)=\)
4. \(+(+1)+(-1)-(+8)+(-2)-(-8)=\)
5. \(+(-5)+(-9)-(+1)-(+8)-(+9)=\)
6. \(-4-4+9+8-7=\)
7. \(-9+1+8-7+2=\)
8. \(+(-7)+(-8)+(+2)+(-4)-(+7)=\)
9. \(+(-8)+(+1)+(+2)+(+7)-(+6)=\)
10. \(-(-5)-(+2)-(+1)+(-7)-(+4)=\)
11. \(7-9+7+5-7=\)
12. \(5-1+3-7+1=\)

---

Reken uit

Verbetersleutel

1. \(-7-9+1-9+7=-17\)
2. \(-(+2)-(-8)-(-1)-(-1)+(+7)=-2+8+1+1+7=15\)
3. \(+(-2)+(-6)-(+5)+(-5)-(+7)=-2-6-5-5-7=-25\)
4. \(+(+1)+(-1)-(+8)+(-2)-(-8)=+1-1-8-2+8=-2\)
5. \(+(-5)+(-9)-(+1)-(+8)-(+9)=-5-9-1-8-9=-32\)
6. \(-4-4+9+8-7=2\)
7. \(-9+1+8-7+2=-5\)
8. \(+(-7)+(-8)+(+2)+(-4)-(+7)=-7-8+2-4-7=-24\)
9. \(+(-8)+(+1)+(+2)+(+7)-(+6)=-8+1+2+7-6=-4\)
10. \(-(-5)-(+2)-(+1)+(-7)-(+4)=+5-2-1-7-4=-9\)
11. \(7-9+7+5-7=3\)
12. \(5-1+3-7+1=1\)