Answer:
centre = (2, - 1), radius = 6
Step-by-step explanation:
Rearrange the equation by placing the x and y terms together and adding 31 to both sides
Given
x² + y² - 4x + 2y - 31 = 0, then
x² - 4x + y² + 2y = 31
Use the method of completing the square
add ( half the coefficient of the x/y term )² to both sides
x² + 2(- 2)x + 4 + y² + 2(1)y + 1 = 31 + 4 + 1
(x - 2)² + (y + 1)² = 36
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r the radius
compare to (x - 2)² + (y + 1)² = 36, then
centre = (2, - 1) and r =
= 6
Answer:
18/21 = 30/35
Step-by-step explanation:
so the problem says 18/21 so if that's the correct ratio to proportion to the answer would be. 30/35. the reason is that you can divide 18 and 21 by 3 to get 6/7 then if you multiply by 5 you get 30/35. Dividing and multiplying both the denominator and numerator keeps the ratio proportional.
Answer:
-2.8
Step-by-step explanation:
1.4(2-4)
1.4(-2)
=-2.8
Answer:
What statements? Just a sentence from this?
Step-by-step explanation:
Answer:
y=3x+19.
Step-by-step explanation:
1) according to the condition the line 't' is parallel to the line 's', it means, the equation of the line 't' is: y=3x+C, where C - unknown number.
2) in order to calculate the 'C', it need to substitute the given coordinates into the equation of the line 't', then:
-2=3*(-7)+C, ⇒ C=19.
3) if C=19 and the equation of the line 't' was y=3x+C, then it is possible to make up the full required equation:
y=3x+19.