tolong diisi dengan caranya no 19 dan 20

1.
[tex] x \: gab = \frac{x1f1 + x2f2}{f 1 + f2} \\ 7.5 = \frac{7.4 \times 30 + 2x2}{30 + 2} \\ 7.5 = \frac{222 + 2x2}{32} \\ 7.5 \times 32 = 222 + 2x2 \\ 240 = 222 + 2x2 \\ 2x2 = 240 - 222 \\ 2x2 = 18 \\ x2 = 9[/tex]
Jawaban : C. 9

2.
[tex]x \: gab = \frac{x1f1 + x2f2}{f1 + f2} \\ 165 = \frac{9 \times 166 + x2}{10} \\ 165 \times 10 = 1.494 + x2 \\ 1.650 = 1.494 + x2 \\ x2 = 1.650 - 1.494 \\ x2 = 156[/tex]
Jawaban : B. 156 cm

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