Remember some simle log rules
loga+logb=log(ab)
xloga=loga^x
means
also, if no base is stated, assume base 10
so
log(2x)=-1 is base 10 and translates to
10^-1=2x
1/10=2x
divide both sides by 2 aka times 1/2
1/20=x
3log(2)+log(x)=3
log(2^3)+log(x)=3
log(8)+log(x)=3
log(8x)=3
base 10
10^3=8x
1000=8x
divide both sides by 8
x=125
Definitions
Independent events= one outcome of an event doesn’t affect the other outcomes
Dependent events= one outcome of an event affects the other outcomes
Examples
Independent= Jack has a standard deck of cards 52 cards( 26 red and 26 black) what is the probability that he picks a red card or a spade?
Dependent= Jack has a standard deck of cards. What is the probability that he picks a red card or a diamond?
a common factor of 5, 15 and 25 is 1 and 5
Answer:176 psychology textbooks and 98 Biology textbooks were sold.
Step-by-step explanation:
Let x represent the number of psychology textbooks that were sold.
Let y represent the number of biology textbooks that were sold.
textbook store sold a combined total of 274 psychology and biology textbooks in a week. This means that
x + y = 274 - - - - - - - - - - -1
The number of psychology textbooks sold was 78 more than the number of biology textbooks sold. This means that
x = y + 78
Substituting x = y + 78 into equation 1, it becomes
y + 78 + y = 274
2y = 274 - 78
2y = 196
y = 98
x = y + 78 = 98 + 78
x = 176
