Tính a) 5 x 5 + 18 b) 5 x 7 + 23 c) 7 x 7 x 2 d) 15 – 6 x 2

a) 5 x 5 + 18

= 25 + 18

= 43

b) 5 x 7 + 23

= 35 + 23

= 58

c) 7 x 7 x 2

= 49 x 2

= 98

d) 15 – 6 x 2

= 15 – 12

= 3