First find the slope using the slope formula M= (y2-y1) divided by (x2-x1) and then take the slope and and the 1st set of points (x1, y1) and plug it into the slope intercept formula which is y-y1=m(x-x1), then you need to add or subtract variables to correlate with the standard form formula which is ax + by = c.
Hope that helps!
Answer:
81
Step-by-step explanation:
let the terms be a,ar,ar²
r=2/3
a+a(2/3)+a(2/3)²=171
multiply by 9
9a+6a+4a=171×9
19 a=171×9
a=(171×9)/(19)
a=9×9=81
Answer: 
<u>Step-by-step explanation:</u>

Answer:
the first one and the fith one
Step-by-step explanation: