To begin, you can divide the equation by 4 to get y-x = 4. Next, the slope-intercept form of any equation is y=Mx+b, so your answer will be y=x+4
Alternate exterior is the answer
If we have 2 coordinates say: (x1,y1) and (x2,y2)
Then the formula for the midpoint is:
((x1+x2)/2,(y1+y2)/2)
And the formula for the distance is:
Sqrt((x2-x1)^2+(y2-y1)^2)
So here we have (-1,-4) and (-7,4)
The midpoint is:
((-1+-7)/2,(-4+4)/2) = (-8/2,0/2) = (-4,0)
The distance is:
Sqrt((-7- -1)^2+(4- -4)^2)
= sqrt((-6^2)+(8^2))
=sqrt(36+64)
=sqrt(100)
=10
Answer: 912
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Work Shown:
The starting term is a1 = 3. The common difference is d = 5 (since we add 5 to each term to get the next term). The nth term formula is
an = a1+d(n-1)
an = 3+5(n-1)
an = 3+5n-5
an = 5n-2
Plug n = 19 into the formula to find the 19th term
an = 5n-2
a19 = 5*19-2
a19 = 95-2
a19 = 93
Add the first and nineteenth terms (a1 = 3 and a19 = 93) to get a1+a19 = 3+93 = 96
Multiply this by n/2 = 19/2 = 9.5 to get the final answer
96*9.5 = 912
I used the formula
Sn = (n/2)*(a1 + an)
where you add the first term (a1) to the nth term (an), then multiply by n/2
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As a check, here are the 19 terms listed out and added up. We get 912 like expected.
3+8+13+18 +23+28+33+38 +43+48+53+58 +63+68+73+78 +83+88+93 = 912
There are 19 values being added up in that equation above. I used spaces to help group the values (groups of four; except the last group which is 3 values) so it's a bit more readable.