7x - 5y = 21....(4,?)...so sub in 4 for x and solve for y
7(4) - 5y = 21
28 - 5y = 21
-5y = 21 - 28
-5y = - 7
y = 7/5
check..
7(4) - 5(7/5) = 21
28 - 35/5 = 21
28 - 7 = 21
21 = 21 (correct)
the other coordinate is 7/5......(4,7/5)
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
Y=4/5+2 this is in slope interception
Answer:
A. 2x + 5(2x + 6) = 12x + 30
Step-by-step explanation:
Infinitely many solutions means the two sides of the equation will be equal to each other, so B and D can be eliminated. Distribute for A and C to check
A. 2x + 5(2x + 6) = 12x + 30
2x + 10x + 30 = 12x + 30
12x + 30 = 12x + 30
C. 2(x + 5) + 2 = 6x + 2(x + 2)
2x + 10 + 2 = 6x +2x + 4
2x + 12 = 8x + 4
You only get the same equation for A, therefore A is the correct answer