Question

cuanto es la siguiente 2x"2+x=55

Answer 1

Por fórmula general.

2x² +x= 55

2x² +x - 55=0

A= 2

B= 1

C= - 55

-b +- √(b²) - 4ac

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

2a

-1 +- √1² - 4(2) (-55)

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

2(2)

-1 +- √ 1 + 440

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

4

-1 +- √441

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

4

-1 +- 21

------------- =

4

X=( - 1 +21)/4

X= 20/4

X1 = 5

X2= (-1 - 21)/4

X2= - 22/4

X2= - 11/2.

COMPROBAMOS

2x² +x= 55

2(5)²+ 5= 55

2(25)+5= 55

50+5= 55

55= 55

2x² +x= 55

2(-11/2)² +(-11/2) =55

2(121/4) - 11/2= 55

121/2 - 11/2= 55

110/2 =55

55= 55.