Lettervormen getalwaarde

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Bereken de getalwaarde

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

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Bereken de getalwaarde

Verbetersleutel

1. \(\begin{align} 2ab+5b+4&=2.a.b+5.b+4 \text{ [met a = 6 en b = 2]}\\&=2.6.2+5.2+4\\&=38\\ \end{align}\)
2. \(\begin{align} 5ab-3b-15&=5.a.b-3.b-15 \text{ [met a = 5 en b = 2]}\\&=5.5.2-3.2-15\\&=29\\ \end{align}\)
3. \(\begin{align} 3ab+4b-1&=3.a.b+4.b-1 \text{ [met a = 3 en b = -5]}\\&=3.3.(-5)+4.(-5)-1\\&=-66\\ \end{align}\)
4. \(\begin{align} 9a+3b&=9.a+3.b \text{ [met a = 3 en b = 3]}\\&=9.3+3.3\\&=36\\ \end{align}\)
5. \(\begin{align} 5ab-5b-2&=5.a.b-5.b-2 \text{ [met a = -4 en b = -3]}\\&=5.(-4).(-3)-5.(-3)-2\\&=73\\ \end{align}\)
6. \(\begin{align} 3a^2-2b&=3.a^2-2.b \text{ [met a = 1 en b = -1]}\\&=3.1^2-2.(-1)\\&=5\\ \end{align}\)
7. \(\begin{align} 9a-9b&=9.a-9.b \text{ [met a = -1 en b = -5]}\\&=9.(-1)-9.(-5)\\&=36\\ \end{align}\)
8. \(\begin{align} 2a^2-6b&=2.a^2-6.b \text{ [met a = -5 en b = -3]}\\&=2.(-5)^2-6.(-3)\\&=68\\ \end{align}\)
9. \(\begin{align} 3a-b&=3.a-1.b \text{ [met a = 4 en b = -1]}\\&=3.4-1.(-1)\\&=13\\ \end{align}\)
10. \(\begin{align} 5ab+2b-12&=5.a.b+2.b-12 \text{ [met a = -1 en b = -5]}\\&=5.(-1).(-5)+2.(-5)-12\\&=3\\ \end{align}\)
11. \(\begin{align} 9a+b&=9.a+1.b \text{ [met a = 2 en b = -1]}\\&=9.2+1.(-1)\\&=17\\ \end{align}\)
12. \(\begin{align} 3a^2+3b&=3.a^2+3.b \text{ [met a = 4 en b = -3]}\\&=3.4^2+3.(-3)\\&=39\\ \end{align}\)