Answer:
y = 21
Step-by-step explanation:
Lovely ratios can figure out what the missing side is.
You can either have x as the numerator or denominator, but keep it consistent, otherwise...wrong answer.
[tex]\frac{6}{7} = \frac{18}{y}[/tex]
Now to figure out what y is, we need to isolate y.
[tex]\frac{6}{7} = \frac{18}{y}\\y*\frac{6}{7} = \frac{18}{y}*y\\\frac{6}{7}y = 18\\\frac{6}{7}y / \frac{6}{7} = 18 / \frac{6}{7}\\y = 21[/tex]
y is 21 when x is 18.
