Answer:
By making ‘a’ the subject, I believe you mean isolate the variable ‘a’.
1/a - 1/b = 1/c : add 1/b to both sides
1/a = 1/b + 1/c : combine the unlike fractions by finding a common denominator, bc is the common denominator
1/a = (1/b)(c/c) + (1/c)(b/b) : simplify
1/a = (c/bc) + (b/bc) : add numerators only, because the denominators match
1/a = (c + b)/bc : multiply both sides by a
1 = (a)[(c + b)/bc] : multiply both sides by the reciprocal of [(c + b)/bc] which is [bc/(b + c)]
1[bc/(b + c)] = a
a = bc/(b + c)
This will not work if c = -b, because then you would be dividing by zero.
Example: 1/2 - 1/3 = 1/6 a = 2, b = 3 c= 6
a = bc/(b + c) => 2 = (3 x 6)/(3 + 6) => 2 = 18/9 => 2 = 2.
Step-by-step explanation:
hello :<span>
<span>an equation of the circle Center at the
A(a,b) and ridus : r is :
(x-a)² +(y-b)² = r²
in this exercice : a = -7 and b = -1 (Center at: A(-7,-1) )
r = AP.... P(8,7)
r² = (AP)²
r² = (8+7)² +(7+1)² =225+64=289 ...... so : r = 17
an equation of the circle that satisfies the stated conditions.
Center at </span></span>A(-7,-1), passing through P(8, 7) is :
(x+7)² +(y+1)² = 289
The point (-15,y ) <span>lies on this circle : (-15+7)² +(y+1)² = 289....(subsct : x= -15)
(y+1)² = 225
(y+1)² = 15²
y+1 = 15 or y+1 = -15
y = 14 or y = -16
you have two points : (-15,14) , (-15, -16)</span>
The Correct Answer Is A = 4 pi symbol r2
