Lettervormen getalwaarde

Bereken de getalwaarde

\(5ab+2b-2\text{ [met a = -2 en b = 2]}\)

\(\begin{align} 5ab+2b-2&=5.a.b+2.b-2 \text{ [met a = -2 en b = 2]}\\&=5.(-2).2+2.2-2\\&=-18\\ \end{align}\)