math b
posted by jojo .
solve each system of equation algebraically:
x2+y2=18
x+y=4

Do you mean the circle
x^2+y^2 = 18 ? 
yes

Making that assumption, we are looking for where the straight line:
y = 1x + 4
which has a slope of 1 and goes through (0,4) and (4,0)
hits the circle with center at the origin and radius 3 sqrt 2 which is about 4.24
Sketch a graph so we will get an idea of how the solution should look.
So
substitute y = x + 4 into the circle
x^2 + (x+4)^2 = 18
x^2 + x^2  8 x + 16 = 18
2 x^2 8 x 2 = 0
x^2  4 x 1 = 0
x = (1/2)[ 4 +/ sqrt (16 +4)]
x = (1/2) [ 4 +/ 2 sqrt 5]
x = 2 +/ sqrt 5
find the y for each of those x values
Respond to this Question
Similar Questions

math
solve the following system of equations algebraically or graphically for x and y: y=xsquare6x+6 yx=4 For an algebraicc solution, show your work here. y=x^26x+6 yx= 4 Let's substitute x4 for y in the first equation. x4 = x^26x+6 … 
math b
solve each system of equations algebraically: x^2+y^2=18 x+y=4 
System of equation
solve algebraically x^2 + y^2 = 16 x  y = 4 
Math
1/2z  1/4w = 1/6 1/2z + 1/4w = 1/6 Solve the system of equations algebraically. 
PreCalculus
PLEASE HELP ME ASAP!!!!!!!!!!!! :) I really need to remember on how to do this equation. Solve the system algebraically. y=25x^2+x 9x+y=3 
math
solve the system algebraically and graphically 32x^2+9y^2=324 3y^2x^2=3 
Math
Solve the system of equations algebraically. Show all of your steps. Y=x^2+2x y=3x+20 
Math
Solve the system of equations algebraically . show all your steps. Y=x^2+2x Y=3x+20 
math homework
solve the system of equations algebraically for x and y { x^2 + y^2 = 26 x + y = 6 a. (1,5) (1,4) b. (4,5) (5,4) c. (5,1) (5,1) d. (1,5) (5,1) e. no solution 
Math
Solve each system algebraically Y=4x9 and y=x3 This is what I have done 4xy9=0 x3+4x9=0 3x=9+3 3x=12 X=4 Than I substituted x in one equation y=43 y=1 Please let me know if I am doing this correctly. Thx