<span>−8x+7y=25 is already in standard form, altho some people would prefer to re-write it as
</span><span>−8x+7y-25 = 0.
You have shared 4 equations here. Next time, please separate them with commas or semi colons, or type just 1 equation per line, for increased clarity. Thanks.</span>
Answer:

Step-by-step explanation:
we would like to expand the following logarithmic expression:

remember the multiplication logarithmic indentity given by:

so our given expression should be

by exponent logarithmic property we acquire:

hence, our answer is A
Answer:
14
Step-by-step explanation:
mass of 100 centimeters of copper wire is 
so, mass of 1 centimeter of copper wire will be 
hence, 14 centimeters of copper wire will provide .28 copper
Only two numbers less than 100 have a factor of 40: 40 (1 x 40) and 80 (2 x 40). Since 40 is a factor of both 40 and 80, 10 must also be a factor - indeed, 40 = 4 x 10 and 80 = 8 x 10.
The two number must be 40 and 80.