\( 1 \leftarrow \quad \begin{array}{l}\text { Use the trigonometric function values of the quadrantal angles to evaluate. } \\ 5 \cos 270^{\circ}-7 \sec 180^{\circ}\end{array} \) \( \begin{array}{l}5 \cos 270^{\circ}-7 \sec 180^{\circ}=\square \\ \\ \text { (Simplify your answer. Type an integer or a fraction.) }\end{array} \)

To evaluate \( 5 \cos 270^{\circ} - 7 \sec 180^{\circ} \), we first need to determine the trigonometric values of the given angles. 1. \( \cos 270^{\circ} = 0 \) because at this angle, the cosine function corresponds to the x-coordinate on the unit circle, which is 0. 2. \( \sec 180^{\circ} \) is the reciprocal of \( \cos 180^{\circ} \). Since \( \cos 180^{\circ} = -1 \), we have \( \sec 180^{\circ} = -1 \). Now, substituting these values into the expression: \[ 5 \cos 270^{\circ} - 7 \sec 180^{\circ} = 5(0) - 7(-1) \] \[ = 0 + 7 = 7 \] Therefore, \( 5 \cos 270^{\circ} - 7 \sec 180^{\circ} = 7 \). The simplified answer is \( \boxed{7} \).