Mathematics
Dmoney2001
2016-04-22 18:12:27
At which points are the equations y = x2 + 5x − 2 and y = x + 1 equal?
ANSWERS
Reindeer
2016-04-22 22:54:12

When they are equal, y=y, so we can say: x^2+5x-2=x+1  subtract x from both sides x^2+4x-2=1  add 2 to both sides x^2+4x=3, now add half the linear coefficient squared, (4/2)^2=4 x^2+4x+4=3+4 now the left side is a perfect square (x+2)^2=7  now take the square root of both sides x+2=±√7  subtract 2 from both sides x=-2±√7 x=-2+√7 and -2-√7 y=x+1 the two points where these equations are equal are: (-2-√7, -1-√7) and (-2+√7, -1+√7) or approximately: (-4.65, -3.65) and (0.65, 1.65)

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