Question

1. Tính tổng: S= -2,5 +\(\frac{23}{4}\)-(-3,25+ \(\frac{1}{2}\)+ \(\frac{13}{2}\))

Answer 1

\(S=-2,5+\frac{23}{4}-\left(-3,25+\frac{1}{2}+\frac{13}{2}\right)\)

\(S=-\frac{5}{2}+\frac{23}{4}-\left(-\frac{13}{4}+\frac{1}{2}+\frac{13}{2}\right)\)

\(S=-\frac{5}{2}+\frac{23}{4}-\left(\frac{15}{4}\right)\)

\(S=-\frac{1}{2}\)

Answer 2

\(S=-2,5+\frac{23}{4}-\left(-3,25+\frac{1}{2}+\frac{13}{2}\right)\)

\(S=-2,5+\frac{23}{4}+3,25-\frac{1}{2}-\frac{13}{2}\)

\(S=\frac{23}{4}-2,5+3,25-7\)

\(S=3,25+3,25-7\)

\(S=6,5-7\)

\(S=-0,5\)