SOLUTION: If 2(x -1) = 14, then x = If 5x + x² > 100, then x is not If 5x - 17 = -x + 7, then x =

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: If 2(x -1) = 14, then x = If 5x + x² > 100, then x is not If 5x - 17 = -x + 7, then x =       Log On


   

Question 457061: If 2(x -1) = 14, then x =
If 5x + x² > 100, then x is not
If 5x - 17 = -x + 7, then x =
Found 2 solutions by Edwin McCravy, MathLover1:
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
If 2(x -1) = 14, then 

    2x - 2 = 14
        2x = 16
         x = 8

-------------------------

If 5x + x² > 100, then 

   x² + 5x - 100 > 0

which has critical values when x² + 5x - 100 = 0

                               x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
                               x+=+%28-5+%2B-+sqrt%28+5%5E2-4%2A1%2A%28-100%29+%29%29%2F%282%2A1%29+ 
                               x+=+%28-5+%2B-+sqrt%2825%2B400%29+%29%2F2+ 
                               x+=+%28-5+%2B-+sqrt%28425%29+%29%2F2+ 
                               x+=+%28-5+%2B-+sqrt%2825%2A17%29+%29%2F2+
                               x+=+%28-5+%2B-+5sqrt%2817%29+%29%2F2+
                               approximately -12.8 or 7.8

Intervals                 (-oo,-12.8)  (-12.8,7.8)   (7.8,oo)   
Test values                   -13            0          8
expression at test value        4         -100          4
expression > 0?                yes          no         yes  


x is not between %28-5+-+5sqrt%2817%29+%29%2F2+ and x+=+%28-5+%2B+5sqrt%2817%29+%29%2F2+, inclusive

---------------------------

If 5x - 17 = -x + 7, then 
        6x = 24
         x = 4    

---------------------------
Edwin

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

If 2%28x+-1%29+=+14, then
2x+-2=14
2x=14%2B2
2x=16
x=16%2F2
x=8

If 5x+%2B+x%5E2+%3E+100, then x is not
5x+%2B+x%5E2-100+%3E+0
x%5E2%2B5x-100+%3E+0.......use quadratic formula and solve x%5E2%2B5x-100+=+0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-5+%2B-+sqrt%28+5%5E2-4%2A1%2A%28-100%29+%29%29%2F%282%2A1%29+

x+=+%28-5+%2B-+sqrt%2825%2B400%29+%29%29%2F2+
x+=+%28-5+%2B-+sqrt%28425%29+%29%29%2F2+
x+=+%28-5+%2B-+20.6%29%2F2+
solutions:
x+=+%28-5+%2B+20.6%29%2F2+
x+=+%2815.6%29%2F2+
x+=+7.8+

or

x+=+%28-5+-+20.6%29%2F2+
x+=+%28-25.6%29%2F2+
x+=+-12.8+

so, x is not x+=+7.8+ or x+=+-12.8+



If 5x+-+17+=+-x+%2B+7, then x =
5x+%2Bx+=+17+%2B+7
6x+=24
x+=24%2F6
x+=4