Answer:
the first one
the first one Step-by-step explanation:
the first one Step-by-step explanation:from the formula Un =ar^n-1
where a is 2
where a is 2 r = 20/2=10
where a is 2 r = 20/2=10 so Un= 10×2^n-1
that's all.....have fun
please be more specific
<em>9.</em>
Step-by-step explanation:
3 * √)0^2 + 3^2)
= 3*3
= 9.