100,200,300,400,500,600,700,800,900
10х+8-(4х-5)=10х+8-4х+5=6х+13
6*(-6,6)+13=-39,6+13=-26,6
42+61+28+39+30=(42+28)+(61+39)+30=70+100+30=100+100=200
4·9·5·2·25=(4·25)·(5·2)·9=100·10·9=1000·9=9000
(33–3):3=10
3*3*3:3=9
(3*3)–(3:3)=8 или 33:3–3=8
(3+3)+(3:3)=7
3*3:3+3=6
(3+3)–(3:3)=5
3*3–(3+3)=3
(3:3)+(3:3)=2
3–3+(3:3)=1