Question

Simultaneous equation

y= x^2
y + 3x = 4

Anyone can help with the steps to do it?

Answer 1

since y=x^2 you can substitute into the second equation

x^2+3x-4=0

what adds to +3 and multiplies to -4?

Answer 2

Start by making both equations equal to y.
y + 3x = 4 <=> y = 4 - 3x.
Then set the equations equal to each other, and solve for x.
x^2 = 4 - 3x
x^2 + 3x - 4 = 0
(x - 1)(x + 4) = 0
The equations intersect when x =1, and x = -4, so you put those values into your original equation.
y = (1)^2; y = (-4)^2.
y = 1; y = 16.
The functions intersect at (1,1) and (-4, 16).

Answer 3

Thank you very much!