Lettervormen getalwaarde

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Bereken de getalwaarde

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

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Bereken de getalwaarde

Verbetersleutel

1. \(\begin{align} 2a-9b&=2.a-9.b \text{ [met a = -1 en b = 2]}\\&=2.(-1)-9.2\\&=-20\\ \end{align}\)
2. \(\begin{align} 4ab+b-5&=4.a.b+1.b-5 \text{ [met a = -2 en b = -2]}\\&=4.(-2).(-2)+1.(-2)-5\\&=9\\ \end{align}\)
3. \(\begin{align} 3a^2+2b&=3.a^2+2.b \text{ [met a = -4 en b = 3]}\\&=3.(-4)^2+2.3\\&=54\\ \end{align}\)
4. \(\begin{align} 5a+2b&=5.a+2.b \text{ [met a = -2 en b = 4]}\\&=5.(-2)+2.4\\&=-2\\ \end{align}\)
5. \(\begin{align} 2a-b&=2.a-1.b \text{ [met a = -4 en b = 3]}\\&=2.(-4)-1.3\\&=-11\\ \end{align}\)
6. \(\begin{align} 8a+8b&=8.a+8.b \text{ [met a = 5 en b = 4]}\\&=8.5+8.4\\&=72\\ \end{align}\)
7. \(\begin{align} 2a^2+4b&=2.a^2+4.b \text{ [met a = 1 en b = -3]}\\&=2.1^2+4.(-3)\\&=-10\\ \end{align}\)
8. \(\begin{align} ab+4b+15&=1.a.b+4.b+15 \text{ [met a = -1 en b = 3]}\\&=1.(-1).3+4.3+15\\&=24\\ \end{align}\)
9. \(\begin{align} 4a^2+4b&=4.a^2+4.b \text{ [met a = -5 en b = -4]}\\&=4.(-5)^2+4.(-4)\\&=84\\ \end{align}\)
10. \(\begin{align} 9a-10b&=9.a-10.b \text{ [met a = -2 en b = -2]}\\&=9.(-2)-10.(-2)\\&=2\\ \end{align}\)
11. \(\begin{align} a^2+3b&=1.a^2+3.b \text{ [met a = 1 en b = 3]}\\&=1.1^2+3.3\\&=10\\ \end{align}\)
12. \(\begin{align} 6a-7b&=6.a-7.b \text{ [met a = 4 en b = -1]}\\&=6.4-7.(-1)\\&=31\\ \end{align}\)