Percent means "per hundred": 12,5% = 12,5/100 = 0,125.
In order to subtract (-) one fraction from another, you need to find a common denominator (bottom). This is done by multiplying (*) the numerator and the denominator in a fraction by the same number:
$$\frac{3}{4}-\frac{5}{6}=\frac{3*3}{4*3}-\frac{5*2}{6*2}=\frac{9}{12}-\frac{10}{12}=-\frac{1}{12}$$
So we get:
$$\frac{0,125}{(-1/12)^{2}}$$
When to fractions are multiplied together, one multiplies the numerator by numerator and denominator by denominator:
$$(-\frac{1}{12})^{2}=(\frac{1}{12})^{2}=\frac{1}{144}$$
So we get:
$$\frac{0,125}{1/144}$$
Multiply the numerator and the denominator by 144:
$$\frac{0,125*144}{1}= 0,125*144$$
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