SOLUTION: where do I begin with this problem? xsq+3x=4

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Question 170017: where do I begin with this problem?
xsq+3x=4
Found 2 solutions by jim_thompson5910, midwood_trail:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2%2B3x=4 Start with the given equation.


x%5E2%2B3x-4=0 Subtract 4 from both sides.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=3, and c=-4


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%283%29+%2B-+sqrt%28+%283%29%5E2-4%281%29%28-4%29+%29%29%2F%282%281%29%29 Plug in a=1, b=3, and c=-4


x+=+%28-3+%2B-+sqrt%28+9-4%281%29%28-4%29+%29%29%2F%282%281%29%29 Square 3 to get 9.


x+=+%28-3+%2B-+sqrt%28+9--16+%29%29%2F%282%281%29%29 Multiply 4%281%29%28-4%29 to get -16


x+=+%28-3+%2B-+sqrt%28+9%2B16+%29%29%2F%282%281%29%29 Rewrite sqrt%289--16%29 as sqrt%289%2B16%29


x+=+%28-3+%2B-+sqrt%28+25+%29%29%2F%282%281%29%29 Add 9 to 16 to get 25


x+=+%28-3+%2B-+sqrt%28+25+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-3+%2B-+5%29%2F%282%29 Take the square root of 25 to get 5.


x+=+%28-3+%2B+5%29%2F%282%29 or x+=+%28-3+-+5%29%2F%282%29 Break up the expression.


x+=+%282%29%2F%282%29 or x+=++%28-8%29%2F%282%29 Combine like terms.


x+=+1 or x+=+-4 Simplify.


So the answers are x+=+1 or x+=+-4


Answer by midwood_trail(310) About Me  (Show Source):
You can put this solution on YOUR website!
x^2+ 3x = 4
Begin by subtracting 4 from both sides and equating to zero.
x^2 + 3x - 4 = 0
We now factor the left side.
x^2 + 3x - 4 becomes (x - 1)(x + 4).
We now set each factor to zero and solve for x.
x - 1 = 0
x = 1
=========
x + 4 = 0
x = -4
=========
Final answer: x = 1 and x = -4