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New photometry and spectroscopy for more than a hundred RR Lyrae stars in two fields located close to the bar of the Large Magellanic Cloud (LMC) are used to derive new accurate estimates of the average magnitude, the local reddening, the luminosity-metallicity relation, and the distance to the LMC. The average apparent luminosity of the RR Lyraes with complete V and B light curves is ⟨V(RR)⟩ = 19.412 ± 0.019 (σ = 0.153), ⟨B(RR)⟩ = 19.807 ± 0.022 (σ = 0.172) in our field A (62 stars) and ⟨V(RR)⟩ = 19.320 ± 0.023 (σ = 0.159), ⟨B(RR)⟩ = 19.680 ± 0.024 (σ = 0.163) in our field B (46 stars). The average V apparent luminosity of the clump stars in the same areas is 0.108 and 0.029 mag brighter than the RR Lyrae level (⟨Vclump⟩ = 19.304 ± 0.002 and 19.291 ± 0.003, in field A: 6728 stars, and B: 3851 stars, respectively). Metallicities from low-resolution spectra obtained with the Very Large Telescope have been derived for 101 RR Lyrae stars, finding an average value of [Fe/H] = -1.48 ± 0.03 (σ = 0.29, on the Harris metallicity scale). An estimate of the reddening within the two fields was obtained (1) from the Sturch method applied to the fundamental-mode pulsators (RRab's) with known metal abundance and (2) from the colors of the edges of the instability strip defined by the full sample of RR Lyrae variable stars. We obtained E(B-V) = 0.116 ± 0.017 and 0.086 ± 0.017 mag in fields A and B, respectively, with a clear-cut indication of a 0.03 mag differential reddening between the two fields. We find that reddening in field A is 0.028 mag smaller than derived by OGLE-II in the same area. On average, the new reddenings are also 0.035 mag larger than derived from Cepheids with projected distances within 2° from the centers of our fields. The new metallicities were combined with the apparent average V0 luminosities to determine the slope of the luminosity-metallicity relation for the RR Lyrae stars. We derived ΔMV(RR)/Δ [Fe/H] = 0.214 ± 0.047, with no clear evidence for the change in slope at [Fe/H] = -1.5, as recently suggested by evolutionary/pulsation and horizontal-branch models.