An arithmetic sequence starts with one number and you add the common difference to the previous term to get the current term So... f(x)=mx+b m=common difference b=starting point f(11)=125=11m+b - f(1)=5=1m+b -------- 120=10m Divide both sides by 10 12=m Your common difference is 12.
Answer: Last option: <span>With the compass point on the intersection of the perpendicular bisectors, put the pencil point on point R and draw a circle.</span>