simultaneous equations?

0 ⤊

simultaneous equations?

solve this equations
y=2(x^2-2x-4)
and
y+4=3x

2007-01-27 11:38:31 · 2 answers · asked by ms dubai 1 in Science & Mathematics ➔ Engineering

2 answers

Take the second equation and solve for x. Then substitute the result for x in the 1st equation. This will give you an equation with nothing but y, which you can then solve.

2007-01-27 11:44:30 · answer #1 · answered by rscanner 6 · 0⤊ 0⤋

y=3x-4
3x-4 = 2x^2 -4x -8
2x^2-7x -4=0
(2x +1)(x-4) = 0
2x+1=0 --> x= 1/2
x-4 = 0 --> x = 4
x = 1/2 or x = 4

2007-01-27 11:48:46 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋