Hi Leigh;
x²+15<5x
You are going to proceed as if the < is an = sign, with one exception. If you multiply or divide both sides by a negative number, then < has to be reversed to >.
x²+15<5x
Let's subtract 5x from both sides...
x^{2}5x+15<5x5x
x^{2}5x+15<0
We can go further, and subtract 15 from both sides...
x^{2}5x+1515<015
x^{2}5x<15
We can multiply both sides by 1...
1(x^{2}5x)>15(1)
x^{2}+5x>15
We can factor...
x(x5)>15
or
x(x+5)>15
10/29/2013

Vivian L.
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