Answer:
231z = 256
Step-by-step explanation:
231z = 256. That's all you have to do. If you wish, divide both sides by 231 to find the value of z.
Common difference d when The first term of an arithmetic sequence is 5, and the tenth term is 13 is 
Step-by-step explanation:
The first term a₁ = 5
The tenth term a₁₀ = 13
Find Common difference d=?
The formula used for arithmetic sequence is:

where aₙ = nth term
a₁= 1st term
d= common difference
Finding d:

So, Common difference d when The first term of an arithmetic sequence is 5, and the tenth term is 13 is 
Keywords: arithmetic sequence
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Answer:
it's d credit to the people who said it
Answer:
B, x=3 y=5
Step-by-step explanation:
x=-7+2y
3y+2x=21
Substitute the x into the other equation
3y+2(-7+2y)=21
y=5
Now put the value into a desired equation
x=-7+2(5)
x=3.
The answer is x=3 and y=5
I hope this helped!