a , 25 + 35 + 76 +65 + 22
= 25+(35+65)+(76+22)
=25+100+100
=225
b , 24 + 25 + 24 x 22
=24(1+22)+25
=552+25
=577
c , 78 - 23 - 25
=78-(23+25)
=78-48
=30
a: \(25+35+76+65+22\)
\(=\left(25+75\right)+\left(35+65\right)+23\)
=223
c: Ta có: 78-23-25
=78-48
=30