Solve for x please... it's for a test and it's really hard
2 answers:
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Answer:
x = - 5, x = 2
Step-by-step explanation:
Using the rules of logarithms
log x - log y = log ( )
x = n ⇔ x =
note that log x = x
Given
log (x² + 3x) - log10 = 0, then
log( ) = 0, thus
=
= 1 ( multiply both sides by 10 )
x² + 3x = 10 ( subtract 10 from both sides )
x² + 3x - 10 = 0 ← in standard form
(x + 5)(x - 2) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 5 = 0 ⇒ x = - 5
x - 2 = 0 ⇒ x = 2
Solution is x = - 5, x = 2