Solve the following simultaneous equations: x^2 + 2y = 9, and y = x + 3.
Label the two equations as the following: x2 + 2y = 9 y = x + 3 Equation 2 can be substituted into equation 1, giving: x2 + 2( x + 3 ) = 9Expanding the brackets and subtracting 9 from both sides means equation 1 becomes x2 + 2x - 3 = 0Then we can factorise this to create (x + 3)(x - 1) = 0Which means x = -3, and x = 1.
Substituting these values into equation 2 gives usy = 0 and y = 4, respectively.So the solutions are (-3, 0) and (1, 4).
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