Lettervormen getalwaarde

Hoofdmenu Eentje per keer  🖨

Bereken de getalwaarde

1. \(5a^2+b\text{ [met a = -2 en b = 1]}\)
2. \(ab-2b-2\text{ [met a = -4 en b = -4]}\)
3. \(4a^2+6b\text{ [met a = -1 en b = 3]}\)
4. \(2ab-2b-4\text{ [met a = 1 en b = -4]}\)
5. \(2a^2-b\text{ [met a = -1 en b = 2]}\)
6. \(5ab+4b+15\text{ [met a = 5 en b = 2]}\)
7. \(3a^2-2b\text{ [met a = 6 en b = -1]}\)
8. \(a^2+5b\text{ [met a = -2 en b = 5]}\)
9. \(5a+8b\text{ [met a = -1 en b = 5]}\)
10. \(5a^2-2b\text{ [met a = 2 en b = 2]}\)
11. \(a^2+2b\text{ [met a = -1 en b = -3]}\)
12. \(4ab-5b+14\text{ [met a = 2 en b = -3]}\)

---

Bereken de getalwaarde

Verbetersleutel

1. \(\begin{align} 5a^2+b&=5.a^2+1.b \text{ [met a = -2 en b = 1]}\\&=5.(-2)^2+1.1\\&=21\\ \end{align}\)
2. \(\begin{align} ab-2b-2&=1.a.b-2.b-2 \text{ [met a = -4 en b = -4]}\\&=1.(-4).(-4)-2.(-4)-2\\&=22\\ \end{align}\)
3. \(\begin{align} 4a^2+6b&=4.a^2+6.b \text{ [met a = -1 en b = 3]}\\&=4.(-1)^2+6.3\\&=22\\ \end{align}\)
4. \(\begin{align} 2ab-2b-4&=2.a.b-2.b-4 \text{ [met a = 1 en b = -4]}\\&=2.1.(-4)-2.(-4)-4\\&=-4\\ \end{align}\)
5. \(\begin{align} 2a^2-b&=2.a^2-1.b \text{ [met a = -1 en b = 2]}\\&=2.(-1)^2-1.2\\&=0\\ \end{align}\)
6. \(\begin{align} 5ab+4b+15&=5.a.b+4.b+15 \text{ [met a = 5 en b = 2]}\\&=5.5.2+4.2+15\\&=73\\ \end{align}\)
7. \(\begin{align} 3a^2-2b&=3.a^2-2.b \text{ [met a = 6 en b = -1]}\\&=3.6^2-2.(-1)\\&=110\\ \end{align}\)
8. \(\begin{align} a^2+5b&=1.a^2+5.b \text{ [met a = -2 en b = 5]}\\&=1.(-2)^2+5.5\\&=29\\ \end{align}\)
9. \(\begin{align} 5a+8b&=5.a+8.b \text{ [met a = -1 en b = 5]}\\&=5.(-1)+8.5\\&=35\\ \end{align}\)
10. \(\begin{align} 5a^2-2b&=5.a^2-2.b \text{ [met a = 2 en b = 2]}\\&=5.2^2-2.2\\&=16\\ \end{align}\)
11. \(\begin{align} a^2+2b&=1.a^2+2.b \text{ [met a = -1 en b = -3]}\\&=1.(-1)^2+2.(-3)\\&=-5\\ \end{align}\)
12. \(\begin{align} 4ab-5b+14&=4.a.b-5.b+14 \text{ [met a = 2 en b = -3]}\\&=4.2.(-3)-5.(-3)+14\\&=5\\ \end{align}\)