Question

(−5.2)+(−3.8)–{(−1.2)–[(−0.5)–(−0.7)]}=?

Answer 1

(−5.2)+(−3.8)–{(−1.2)–[(−0.5)–(−0.7)]}

Just use your BEDMAS rules, but we only have to worry about brackets, which are worked from the most inside to the outer.
(−5.2)+(−3.8)–{(−1.2)–[(−0.5)–(−0.7)]}

= (−5.2)+(−3.8)–{(−1.2)–[−0.5 + 0.7]}
= (−5.2)+(−3.8)–{(−1.2)– 0.2}
= -5.2 - 3.8 - {-1.4}
= -5.2 - 3.8 +1.4
= -7.6

or you can just google it:
www.google.ca/search?rlz=1C6CHFA_enCA690CA691&source=hp&ei=882oXM_nBanEjgSD04KYAg&q=%28%E2%88%925.2%29%2B%28%E2%88%923.8%29%E2%80%93%28%28%E2%88%921.2%29%E2%80%93%28%28%E2%88%920.5%29%E2%80%93%28%E2%88%920.7%29%29%29&btnK=Google+Search&oq=%28%E2%88%925.2%29%2B%28%E2%88%923.8%29%E2%80%93%28%28%E2%88%921.2%29%E2%80%93%28%28%E2%88%920.5%29%E2%80%93%28%E2%88%920.7%29%29%29&gs_l=psy-ab.3...2585.21511..22184...1.0..0.316.1277.7j2j0j1......0....2j1..gws-wiz.....6..35i39.fUBBWWpfsA8