(30 points) what are the y intercepts of the circle whose equation is (x+2)^2+(y-4)^2=13? a. 1 and 7 b. 4 plus or minus radical 17 c. there are no y intercepts !

Hello from MrBillDoesMath!

 Choice C

Discussion:

The y-intercepts are the x values where y = 0.   Substituting y = 0 in the equation gives

(x+2)^2 +  (0-4)^2 = 13 =>

(x+2)^2 + 16 = 13 =>

Subtract 16 from both sides

(x+2)^2 = 13 - 16 = -3     (*)

The square of a real number is greater than or equal to 0. (Not true for complex numbers). The left side of (*) is therefore >= 0 but as also equals -3. This is not possible so there is no solution to the equation. Choice C.

Thank you,

MrB

2^y = ln 5, or   y(ln 2) = ln 5.   solving for y,   y = (ln 5) / (ln 2).   y=5

step-by-step explanation:

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: