Good evening ,
Answer:
Is his formula correct and how do you know : <em>Yes</em>
Is it an explicit or recursive formula : <em>explicit </em>
Step-by-step explanation:
an = a1 + (n-1)r
a1 = 5
r = 8-5 = 3
Then an = 5 + 3(n-1).
:)
The negative in front of the second bracket means that it's times by -1 so each of their signs switches:
3m^2+2n-m^2-2n
Add like terms
2m^2
the 2n cancels out
Let: x be Amy's marbles
3x be Robin's marbles
15+3x be Sam's marbles
x+3x+15+3x=99
7x+15=99
7x=99-15 (transfer 15 to the right side of the equation, then minus)
7x/7=84/7 (divide both sides of the equation by 7)
x=12
Now substitute:
x = 12 (Amy's)
3x = 3*12 = 36 (Robin's)
15+3x = 15+3*12 = 51 (Sam's)
12+36+51 = 99
Therefore, Amy has 12 marbles, Robin has 36 marbles and Sam has 51 marbles.
Answer:
the answer is
The point (1, −5) lie in the solution set