(-48)+79+(-33)+(-76)+241
(-78)+129+(-47)+(-71)+192
|-33|+(73)+(-41)+|22|
|-22|+(-92)+(-56)+22
|-92|+|22|+(-14)+29
|78|+|-93|+(-27)+(-13)
4524-(-864+999)-(-3699+3999)
1+3+5…+99+(-2)+(-4)+…+(-98)
(-1)+2+(-3)+4+…+(-99)+100
1+(-3)+5+(-7)+..+97+(-99)+101
Đáp án:
l) 2499
Giải thích các bước giải:
\(\begin{array}{l}
a)\left( { – 48} \right) + 79 + \left( { – 33} \right) + \left( { – 76} \right) + 241\\
= \left( { – 48 – 33 – 76} \right) + \left( {79 + 241} \right)\\
= – 157 + 320 = 163\\
b)\left( { – 78} \right) + 129 + \left( { – 47} \right) + \left( { – 71} \right) + 192\\
= \left( { – 78 – 47 – 71} \right) + \left( {129 + 192} \right)\\
= – 196 + 321 = 125\\
c)\left| { – 33} \right| + \left( {73} \right) + \left( { – 41} \right) + \left| {22} \right|\\
= 33 + 73 – 41 + 22 = 87\\
d)\left| { – 22} \right| + \left( { – 92} \right) + \left( { – 56} \right) + 22\\
= 22 – 92 – 56 + 22 = – 104\\
e)\left| { – 92} \right| + \left| {22} \right| + \left( { – 14} \right) + 29\\
= 92 + 22 – 14 + 29 = 129\\
f)\left| {78} \right| + \left| { – 93} \right| + \left( { – 27} \right) + \left( { – 13} \right)\\
= 78 + 93 – 27 – 13 = 131\\
g)4524 – \left( { – 864 + 999} \right) – \left( { – 3699 + 3999} \right)\\
= 4524 – 135 – 300\\
= 4089\\
h)1 + 3 + 5… + 99 + \left( { – 2} \right) + \left( { – 4} \right) + … + \left( { – 98} \right)\\
= \dfrac{{\left( {1 + 99} \right)\left( {\dfrac{{99 – 1}}{2} + 1} \right)}}{2} + \dfrac{{\left( { – 98 – 2} \right)\left( {\dfrac{{ – 98 + 2}}{2} + 1} \right)}}{2}\\
= 2500 + 2350\\
= 4850\\
k)\left( { – 1} \right) + 2 + \left( { – 3} \right) + 4 + … + \left( { – 99} \right) + 100\\
= \left( { – 1 – 3 – … – 99} \right) + \left( {2 + 4 + … + 100} \right)\\
= \dfrac{{\left( { – 1 – 99} \right)\left( {\dfrac{{ – 99 + 1}}{2} + 1} \right)}}{2} + \dfrac{{\left( {2 + 100} \right)\left( {\dfrac{{100 – 2}}{2} + 1} \right)}}{2}\\
= 2400 + 2550 = 4950\\
l)1 + \left( { – 3} \right) + 5 + \left( { – 7} \right) + .. + 97 + \left( { – 99} \right) + 101\\
= \left( {1 + 5 + … + 101} \right) + \left( { – 3 – 7 – … – 99} \right)\\
= \dfrac{{\left( {1 + 101} \right)\left( {\dfrac{{101 – 1}}{4} + 1} \right)}}{2} + \dfrac{{\left( { – 3 – 99} \right)\left( {\dfrac{{ – 99 + 3}}{4} + 1} \right)}}{2}\\
= 1326 + 1173 = 2499
\end{array}\)