This is a word problem signifying an algebraic expression.
Translating this to mathematics:

add 4 to both sides.
divide 16 to both sides.
this is:
Answer: a) c(x) = 0.124x + 1.1, b) 13 units
Step-by-step explanation: Revenue function = R(x) = 0.21x
Profit function = p(x) = 0.086 - 1.1
Cost function = c(x) =?
A)
Recall that profit = total revenue - total cost
Hence, total cost = total revenue - profit
c(x) = 0.21x - (0.086x - 1.1)
c(x) = 0.21x - 0.086x + 1.1
c(x) = 0.124x + 1.1
B)
Break even point is the point where total revenue equals total cost
R(x) = c(x)
0.21x = 0.124x + 1.1
0.21x - 0.124x = 1.1
0.086x = 1.1
x = 1.1/0.086
x = 12.79 which is approximately 13 units
5x+20+16
the expression is 5x+36
Answer:
Step-by-step explanation:
general equation for a circle at the origin is
x² + y² = r²
if the circle center is (x₀, y₀), the formula is
(x - x₀)² + (y - y₀)² = r²
(x - 8)² + (y - 10)² = 36
Multiply the top one by 3 for x, so you can eliminate x and find y
then plug in the y into one of the equations to find x