im sorry but can you show more so i can help you Step-by-step explanation:
Answer:

Step-by-step explanation:
combine like terms. not trying to be mean, but that all you have to do.
Answer:
the answer would be 1 but there are no equations
Step-by-step explanation:
Y = x - 7 ---------- (1)
5x + 2y = 7 ------ (2)
Sub (1) into (2):
5x + 2(x -7) = 7
5x + 2x - 14 = 7
7x - 14 = 7
7x = 7 + 14
7x = 21
x = 3 ----- -sub into (1)
y = x - 7
y = 3 - 7
y = -4
Ans: x = 3, y = -4
We can determine this to be a Geometric Sequence with:
a = 2
r = 1/2
an = ?
We must first find an. We know that an = 1/256, therefore we can use this formula to discover an:
an = a * r^n-1
1/256 = 2 * 1/2^n-1
<span>1/256 / 2 = 1/2^n-1
</span>1/512 = 1/2^n-1
<span>log(1/512) = log(1/2^n-1)
</span>9 = n - 1
10 = n
Therefore, we know an = 10
Now we input it into this equation and solve:
Sn = a(1-r^n/1-<span>r)
</span>Sn = 2(1-1/2^10/1-1/2<span>)
</span>Sn = 2(1023/1024 / 1 / 2)
Sn = 2(1023/1024 * 2 / 1)
<span>Sn = 2(2046/1024)
</span><span>Sn = 2(1023/512)
</span>Sn = 1023/256
Sn = 3.992
Geez, that took awhile... xD