[tex]3)a)100(0.01 + 0.02 + 0.03 + ... + 0.09)[/tex]
[tex] = 100 \times 0.01 + 100 \times 0.02 + 100 \times 0.03 + ... + 100 \times 0.09[/tex]
[tex] = 1 + 2 + 3 + ... + 9[/tex]
[tex] = \frac{9(9 + 1)}{2} [/tex]
[tex] = \frac{9 \times 10}{2} [/tex]
[tex] = \frac{90}{2} [/tex]
[tex] = 45[/tex]
[tex]b)5.8 \times 1.4 + 5.8 \times 3.6 + 5.8 \times 3.2 + 5.8 \times 1.8[/tex]
[tex] = 5.8(1.4 + 3.6 + 3.2 + 1.8)[/tex]
[tex] = 5.8 \times 10[/tex]
[tex] = 58[/tex]
