9x^2 +x = 3^4 solve exponential equation

x

=

−

1

± √

2917

18

Forma

decimal: x = 2.94495880

...

,

− 3.05606991

Step-by-step explanation:

Review both cases and pick the most appropriate answer

Step-by-step explanation:

First case where it's 9(x^2):

9x^2 + x = 3^4

9x^2 + x = 81

9x^2 + x - 81 = 0

x = b±√(b²-4ac) / 2a

x = 1±√(1²-4(9)(-81)) / 2(9)

x = 1±√(1+2916) / 18

x = 1±√(2917) / 18

x = 1+√(2917) / 18

x = 1-√(2917) / 18

Second case where it's (9x)^2:

(9x)^2 + x = 3^4

(9x)^2 + x = 81

81x^2 + x = 81

81x^2 + x - 81 = 0

x = b±√(b²-4ac) / 2a

x = 1±√(1²-4(81)(-81)) / 2(81)

x = 1±√(1+26244) / 162

x = 1±√(26245) / 162

x = 1+√(26245) / 162

x = 1-√(26245) / 162

-13

step-by-step explanation:

f(x)=2x-5 for f(-4)

f(-4)   means let x=-4

f(-4) = 2(-4) -5

f(-4) =-8-5

      = -13