Answer:
Step-by-step explanation:
<u><em># 21.</em></u>
÷ ( - 0.35 ) = -
÷
= -
÷
= -
×
= -
<em>(B).</em>
<u><em># 22.</em></u>
( -
) ÷ ( - 2.5 )
=
= 3.5
=
=
= 9.75
( 3.5 - 9.75 ) ÷ ( - 2.5 ) = ( - 6.25 ) ÷ ( - 2.5 ) = 2.5 <em>(D).</em>
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
