Answer: Option B.
Step-by-step explanation:
If a varies directly with b then when a increases b it also increases by a factor k.
Then we can write that
We know that when a = 28 then b = 7. So
Therefore the equation of proportionality is:
So when 
then:
Answer:
Step-by-step explanation:
see the attached figure with letters to better understand the problem
we know that
In the right triangle ABD
In the right triangle BCD
remember that
m< BAD=m<CBD
therefore
equate the equations
The answer is C.
You need you use Pythagoras theorem 2 times to have 2 equations with the same sides i.e. for example a2 + b2 = 81 and a2 - b2 = 9.
You can do it as you have different triangles but with the same sides.
Answer:
-3/2
Step-by-step explanation:
