Find \( -5 \frac{1}{4}\left(-2 \frac{1}{2}\right) \). Write in the simplest form

To solve the expression \( -5 \frac{1}{4}\left(-2 \frac{1}{2}\right) \), we first convert the mixed numbers to improper fractions. For \( -5 \frac{1}{4} \): \[ -5 \frac{1}{4} = -\left(5 \times 4 + 1\right) / 4 = -\frac{21}{4} \] For \( -2 \frac{1}{2} \): \[ -2 \frac{1}{2} = -\left(2 \times 2 + 1\right) / 2 = -\frac{5}{2} \] Now, we multiply the two improper fractions: \[ -\frac{21}{4} \times -\frac{5}{2} = \frac{21 \times 5}{4 \times 2} = \frac{105}{8} \] Finally, to express \( \frac{105}{8} \) as a mixed number, we perform the division: \[ 105 \div 8 = 13 \quad \text{(remainder 1)} \] Thus, \( \frac{105}{8} = 13 \frac{1}{8} \). So, the answer in the simplest form is: \[ \boxed{13 \frac{1}{8}} \]