Answer:
a) (-2,2), (-1,-1), (1,-1), (3,7)
b) x=1.4
1. 20,000,000 = 20 million
2. 200,000 = 200 thousand
3. 20,000 = 20 thousand
4. 2 = 2 ones? (I'm not sure about this one)
Step-by-step explanation:
HERE,
as,it is a right angle triangle,
x=

radius = 7
the equation of a circle in standard form is
(x-a)² + (y-b)² = r²
where (a, b) are the coordinates of the centre and r is the radius
To obtain this form ' complete the square ' on both the x and y terms
x² + 2(1)x + 1 + y² + 2(3)y + 9 = 39 + 1 + 9
(x+1)² + (y+3)² = 49 ← in standard form
with centre (1, 3) and r = √49 = 7