Well, there are different ways to do this if you are really familiar with fractions, but "officially" :P
1) convert mixed numbers to improper fractions.
rule: a b/c = (ac+b)/c
2) make all fractions have a common denominator...
a/b+c/d
(a/b)(d/d)+(c/d)(b/b)
(ad/bd)+(cb/bd)
3)
The simplify your final answer with greatest common denominator or convert back to mixed number if needed...
Answer:
Is there a x somewhere or is that litteraly how the equation is?
If so, -7 multiplied by 2 is -14,
-1 times -7 is 7,
add it together and you get
-7=28,
you could add 7 to both sides or subtract 28 from both sides and you'll get either 0=35 or -35=0
which would make the solution false since both sides are not the same

It looks like your first selection (a) is appropriate.
Answer:
3,724
Step-by-step explanation: Length x width x height
19 x 14 x 14
19 x 14 = 266
266 x 14 = 3,742
hope this helped :)
Answer:
a) Only the first one is an identity.
Step-by-step explanation:
1). 8 cos O tan O csc O = 8 simplifies to:
cos O tan O csc O = 1
cos O * (sin O / cos O) * (1 /sin O)
= cos O sin O / cos O sin O
= 1
So it is identity.
2) 13 sec^2 O/ cos^2 O - tan^2 O / cos^2O
= 13 sec^2 O - tan^2 O / cos^2 O
Now sec^2 O = 1 + tan^2 O, so we have:
(13( 1 + tan^2 O) - tan^2 O) / cos^2 O
= (12 tan^2 O + 13) / cos^2 O
This is not always = 2 so its not an identity.