Question

Упрости выражения.
15а•4
3b•12
17а•5
11а•7
21d - 18d + 3
14а +а+9+4

Answer 1

$15a*4=60a\\\\3b*12=36b\\\\17a*5=85a\\\\11a*7=77a\\\\21d-18d+3=(21-18)d+3=3d+3\\\\14a+a+9+4=15a+13$