First verify the base case by inserting values so you can assume it holds for it n
for n+1 add the next term 6*(n+1) of the sum to both sides:
6 + 12 + 18 + ... + 6n +6(n+1)= 3n(n+1)+6(n+1)
=(n+1)(3n+6)
=3(n+1)(n+2)
=3(n+1)((n+1)+1)
=term if you had inserted n+1 instead of n, proving correctness
<span />
Well, first we can rule out B and D. When you multiply a positive number by a negative number, you will get a negative number. Since the product of this equation is a positive, we can rule these 2 out. Now we are left with A and C. There are 2 ways you can solve this. You can divide 144 by 16 or 36, or multiply 4 by 16 or 36. I perfer to multiply 4 by A or C. 4 x 16 = 64. So we can rule that one out. SO your answer is C.
Step-by-step explanation:
This figure has 1 line of symmetry
A right triangle has an angle that is 90 degrees.
An acute triangle has all three angles less than 90 degrees.
An obtuse triangle has one angle greater than 90 degrees.
Hope that helps.
