Answer:
b=25
Step-by-step explanation:
12/15 = 20/b, b[tex]\neq[/tex]0
4/5 = 20/b
4b = 100
b = 25, b [tex]\neq[/tex] 0
b = 25
25
12/15=20/b
cross multiply
12b=20*15
12b=300
b=300/12