Algebra problem?

Question

solve the system of of equations: y=x^2+4x-9 y=-x-3

Answer 1

Use substitution. Since you know y = -x - 3 , substitute this for y in the first equation and solve for x.

y = x² + 4x - 9

-x - 3 = x² + 4x - 9

0 = x² + 5x - 6

0 = (x+6)(x-1)

So, x =1 or x = -6

Now substitute these values for x to solve for y:

If x = 1: y = -x-3 = -1-3 = -4
If x = -6: y = -x-3 = 6-3 = 3

So you have two solutions for this problem: (1,-4) and (-6,3)

You can think of your problem like this: your two equations are two graphs on the x,y-plane. The first one is a parabola of some sort; the second one is a straight line. Our two ordered pairs in our solution are the two points where the two graphs intersect.

~ ♥ ~

Answer 2

y=x^2+4x-9
y=-x-3 substitute
-x-3=x^2+4x-9 add x+3 to both sides
0=x^2+5x-6
x^2+5x-6=0
(x+6)(x-1)=0
x+6=0
x=-6
x-1=0
x=1

x=-6, 1

Answer 3

y = x^2 + 4x - 9
y = -x - 3

x^2 + 4x - 9 = -x - 3
x^2 + 5x - 6 = 0
(x + 6)(x - 1) = 0
x = -6 or 1

y = -1 - 3 = -4
y = -(-6) - 3 = 6 - 3 = 3

ANS : (-6,3) and (1,-4)

Answer 4

So who gets the points? Intel kni who gave correct instructions about what to do (did you need more than this?), or Gopal the first to give you the x values, or I ♥ AUG who gave a clear and detailed explanation and found the y values for you too?

Answer 5

simplify and solve
x^2+4x-9 =-x-3

then plug it into 2nd equation to get y.

Answer 6

x-3 = x^2 - 4x -9

x^2 - 5x - 6=0
(x-3)(x-2)=0

3,2

Answer 7

(-x-3)=x^2+4x-9
x^2+5x-6=0
(x+6)(x-1)=0
x=-6 or 1

Answer 8

Factor the polynomial, then bring x to one side and solve!