Lettervormen getalwaarde

Hoofdmenu Eentje per keer  🖨

Bereken de getalwaarde

1. \(2ab+4b-12\text{ [met a = 4 en b = -3]}\)
2. \(3a+6b\text{ [met a = 1 en b = 4]}\)
3. \(5ab-b-15\text{ [met a = 4 en b = 5]}\)
4. \(7a+9b\text{ [met a = 1 en b = 4]}\)
5. \(8a-5b\text{ [met a = 4 en b = -4]}\)
6. \(4ab+3b-2\text{ [met a = 3 en b = 1]}\)
7. \(2ab-5b-11\text{ [met a = -5 en b = 6]}\)
8. \(a^2+3b\text{ [met a = -1 en b = -2]}\)
9. \(ab-5b-5\text{ [met a = -4 en b = -2]}\)
10. \(3ab-4b-8\text{ [met a = -4 en b = 5]}\)
11. \(5ab-4b+9\text{ [met a = -1 en b = -1]}\)
12. \(2ab+2b+1\text{ [met a = -5 en b = -4]}\)

---

Bereken de getalwaarde

Verbetersleutel

1. \(\begin{align} 2ab+4b-12&=2.a.b+4.b-12 \text{ [met a = 4 en b = -3]}\\&=2.4.(-3)+4.(-3)-12\\&=-48\\ \end{align}\)
2. \(\begin{align} 3a+6b&=3.a+6.b \text{ [met a = 1 en b = 4]}\\&=3.1+6.4\\&=27\\ \end{align}\)
3. \(\begin{align} 5ab-b-15&=5.a.b-1.b-15 \text{ [met a = 4 en b = 5]}\\&=5.4.5-1.5-15\\&=80\\ \end{align}\)
4. \(\begin{align} 7a+9b&=7.a+9.b \text{ [met a = 1 en b = 4]}\\&=7.1+9.4\\&=43\\ \end{align}\)
5. \(\begin{align} 8a-5b&=8.a-5.b \text{ [met a = 4 en b = -4]}\\&=8.4-5.(-4)\\&=52\\ \end{align}\)
6. \(\begin{align} 4ab+3b-2&=4.a.b+3.b-2 \text{ [met a = 3 en b = 1]}\\&=4.3.1+3.1-2\\&=13\\ \end{align}\)
7. \(\begin{align} 2ab-5b-11&=2.a.b-5.b-11 \text{ [met a = -5 en b = 6]}\\&=2.(-5).6-5.6-11\\&=-101\\ \end{align}\)
8. \(\begin{align} a^2+3b&=1.a^2+3.b \text{ [met a = -1 en b = -2]}\\&=1.(-1)^2+3.(-2)\\&=-5\\ \end{align}\)
9. \(\begin{align} ab-5b-5&=1.a.b-5.b-5 \text{ [met a = -4 en b = -2]}\\&=1.(-4).(-2)-5.(-2)-5\\&=13\\ \end{align}\)
10. \(\begin{align} 3ab-4b-8&=3.a.b-4.b-8 \text{ [met a = -4 en b = 5]}\\&=3.(-4).5-4.5-8\\&=-88\\ \end{align}\)
11. \(\begin{align} 5ab-4b+9&=5.a.b-4.b+9 \text{ [met a = -1 en b = -1]}\\&=5.(-1).(-1)-4.(-1)+9\\&=18\\ \end{align}\)
12. \(\begin{align} 2ab+2b+1&=2.a.b+2.b+1 \text{ [met a = -5 en b = -4]}\\&=2.(-5).(-4)+2.(-4)+1\\&=33\\ \end{align}\)