√25²-24²=√(25-24)(25+24)=√49=7
√(√113²-112²)/19²-11²=√15/(19-11)(19+11)=√15/8*30=√1/2*2³=√1/2⁴=1/4
учтено √113²-112²=√(113-112)(113+112)=√225=15
√(313²-312²)(82²-18²)=√(313-312)(313+312)(82-18)(82+18)=
=√1*625*64*100=25*8*10=2000
√12²*(-0,3)²=12*0,3=3,6