SOLUTION: Find the x-intercepts. y = x^2 + 4x - 1

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Question 172484This question is from textbook Introductory Algebra
: Find the x-intercepts.
y = x^2 + 4x - 1 This question is from textbook Introductory Algebra

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!
y+=+x%5E2+%2B+4x+-+1
Solve by Quadratic:
where------->system%28a=1%2Cb=4%2Cc=-1%29
Then,
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x=%28-4%2B-sqrt%284%5E2-4%2A1%2A-1%29%29%2F%282%2A1%29=%28-4%2B-sqrt%2816%2B4%29%29%2F2
x=%28-4%2B-sqrt%2820%29%29%2F2=%28-4%2B-4.472136%29%2F2
2 values:
x=%28-4%2B4.472136%29%2F2=0.472136%2F2=highlight%280.2360679%29
x=%28-4-4.472136%29%2F2=-8.472136%2F2=highlight%28-4.236068%29
let's see the graph:

Thank you,
Jojo