The square of a number decreased by twice the number is equal to 28 more than the number. Find all possible values for the number

  -4 or 7

Step-by-step explanation:

Let x represent the number. Then the problem statement tells us ...

  x^2 -2x = 28+x

  x^2 -3x = 28 . . . . . subtract x

  x^2 -3x +2.25 = 30.25 . . . . add the square of half the x coefficient

  (x -1.5)^2 = 30.25 . . . . . . . . write the left side as a square

  x -1.5 = ±5.5 . . . . . . . . . . . . take the square root

  x = 1.5 ±5.5 = {-4, 7} . . . . . . . add 1.5

The number may be either -4 or 7.

nope.   happens to me as well.

-aparri

x =-.20752

step-by-step explanation:

4^(x+2)=12

4^(x+2)=12

take the log base 4 on each side

log 4 (4^(x+2) = log 4(12)

we know log b(a^y) = y log b (a)

(x+2) log 4(4) = log 4 (12)

x+2 = log 4 (12)

we know   logb c = loga c/loga b

we want to convert to base 10   so a = 10

by default, we do not write the 10   c = 4   and b = 10

log4 10 = log 12/log 4

log4 10 = log 12/ log 4

x+2 = log 12/ log 4

subtract 2 from each side

x +2 -2 = log 12/ log 4 -2

x = 1.79248125 -2

x =-.20752