a.1) (29+30)×6=59×6=354

  2)(29+30)×6=29×6+30×6=354

b.1) (70+20)×6 = 90 × 6 = 540

 2) (70+20)×6 = 70×6 + 20×6 = 540

c.1) (5+4)×80 = 9×80 = 720

 2) (5+4)×80 =5 × 80 + 4 × 80 = 720

d.1) (3+4)×90 = 7 × 90 = 630

 2) (3+4)×90 = 3 × 90 + 4 × 90 = 630

e.1) (90+6)×2 = 96 × 2 = 192

 2) (90+6)×2 = 90 × 2 + 6 × 2 = 192

f.1) 5×(60+3) = 5 × 63 = 315

 5×(60+3) = 5 × 60 + 5 × 3 = 315