What is the greatest solution of x in the equation x2 + 8x - 30 = 18? Enter your answer in the box.

9514 1404 393

  x = 4

Step-by-step explanation:

Subtracting 18,  we have the equation ...

  x^2 +8x -48 = 0

  (x +12)(x -4) = 0 . . . . . factored form

The values of x that make these factors zero are the solutions:

  x = -12, x = 4

The greatest solution is x=4.

Greatest solution of x = 4

Step-by-step explanation:

x² + 8x - 30 = 18

subtract 18 from both sides

x² + 8 x - 30 - 18 = 18 - 18

x ² + 8 x - 48 = 0

split 8x in middle form

x² + ( 12 x - 4 x ) - 48 = 0

factor out x from the first pair

x ( x + 12 ) - ( 4 x- 48 ) = 0

factor out 4 from the second pair

x ( x + 12) - 4 ( x + 12 ) = 0

x + 12 is common factor

x ( x + 12) - 4 ( x + 12 ) = 0

Group common factor

(x - 4) ( x + 12 ) = 0

When the product of factors equal 0, at least one factor is 0.

x - 4 = 0

x = 4

similarly,

x + 12 = 0

x = - 12

Greatest solution of x = 4

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584

addition

step-by-step explanation: