Answer:
an = 1/2 (n) (n+1)
Step-by-step explanation:
1,3,6,10,.........
3-1=2
6-3=3
Each term is different so there is no common difference. It is not an arithmetic sequence
3/1=3
6/3 =2
Each term is different so there is no common ratio. It is not a geometric sequence
1 3 6 10
+2 +3 +4
a1 = 1
a2 = 3
a3 = 6 = 2*3
a4 = 10 = 2*5
Answer:
x=3, y=0.8
Step-by-step explanation:
8x+5y=28
4x+5y=16
Subtract the second simultaneous equation from the first.
You are left with: 4x=12
12/4=3
x=3
Substitute this back into one of the equations.
8(3)+5y=28
8*3=24
28-24=4
4=5y
4/5=0.8
y=0.8
Answer:
Step-by-step explanation:
Perimeter = 4c + 9 + 7c - 5 + 5c + 2 + 5c - 3
= 4c +7c + 5c +5c + 9 - 5 + 2 - 3
= 21c + 3
L=16
W=21
Set up a systems of equations:
x=length
y=width
xy=336
x+5=y
Use substitution to solve:
x(x+5)=336
x^2+5x=336
Solve using factoring:
x^2+5x-336=0
(x-16)(x+21)=0
x=16 and x= -21
Since length can't be negative, l=16
To find width, plug length into the first equation:
(16)y=336
y=21
So...
L=16
<span>W=21</span>
