Question

15=5^x+3 -7. Solve for x, round to nearest thousandths PLEASE AND THANK YOU

Answer 1

i take it it is \[15=5^{x+3}-7\] right ?

Answer 2

yes @satellite73

Answer 3

step one
add 7 to both sides, what do you get ?

Answer 4

22=5^x+3

Answer 5

@satellite73

Answer 6

yes, then use the change of base formula
do you know it?

Answer 7

x+3=log5 22
?? @satellite73

Answer 8

yes but that won't help you get a number, that is equivalent logarithmic form

Answer 9

it says "nearest thousandths" so they want a decimal out of you

Answer 10

\[b^x=A\iff x=\frac{\ln(A)}{\ln(b)}\] is the change of base formula, something you can put in a calculator to get an answer

Answer 11

you got \[5^{x+3}=22\] so \[x+3=\frac{\ln(22)}{\ln(5)}\]

Answer 12

i got

Answer 13

x+3=1.920

Answer 14

i didn't do it but i am sure you can

Answer 15

http://www.wolframalpha.com/input/?i=log%2822%29%2Flog%285%29-3

Answer 16

thank you thank u i got it !
i have one more question please??

Answer 17

sure

Answer 18

9x^2-6x+5=0

Answer 19

describe the solutiona for this quadratic equation

Answer 20

solutions

Answer 21

describe as in solve or describe as in "two real, one real, two complex"?

Answer 22

describe in as if it has, 2 rational roots, 2 complex roots, 1 rational double root, or 2 irrational roots

Answer 23

probably the second one
compute the discriminant \[b^2-4ac\] for \(a=9,b=-6,c=5\)

Answer 24

got 216

Answer 25

it if is a perfect square you get two rational ones
if it is positive but not a perfect square they are irrational, it if is negative they are complex, and if it is 0 there is one rational double root

Answer 26

so confused, so would it be 2 complex roots??

Answer 27

yes, but the discriminant is not what you wrote

Answer 28

\[(-6)^2-4\times 9\times 5=?\]

Answer 29

-144?

Answer 30

yes
negative, so two complex roots

Answer 31

thank you!