300 - (90+70) + (86-46) 90: (10*9) : (9:9) 0*8+7 0 * (8+7) 91:13*7 84: (14*3)

300 - (90+70) + (86-46) = 180

1) 90+70=160

2) 86-46=40

3) 300-160 = 140

4) 140+40 = 180

90: (10*9) : (9:9) = 1

1) 10*9=90

2) 9/9=1

3) 90/1=90

4) 90/90=1

0 * 8 + 70 * (8 + 7) = 1050

8+7=15

0*8=0

15*70=1050

0+1050=1050

90: (10*9) : (9:9) = 1

10*9=90

9/9=1

90/90=1

1/1=1

91:13*7 = 49

91/13=7

7*7=49

84 / (14 * 3) = 2

14*3=42

84/42=2