Question

If 4y = 20 then 2y - 1 equals what number

Answer 1

4y = 20
y = 20 / 4
y = 5

2y - 1 = ?
2(5) - 1 = ?
10 - 1 = 9

Answer 2

$4y=20\\20\div4=5\\y=5\\\\2y-1;y=5\\2\times5-1\\10-1\\\boxed9\\\\\star\bowtie\star$