4tanA%1-tan^4A=tan2A+sin2A

See prove of the identity below

Step-by-step explanation:

Recall that the following difference can be factored out as:

Now we look at the right side of the equal sign, and recall the identity that relates the sine of a double angle 2A with an expression in terms of the tan(A):

and similarly, the tangent of the double angle "2A" can be written as:

We can then combine the two expressions on the right using  the common denominator: :

And we have proved the identity since the right hand side becomes exactly equal to the left hand side of the equal sign.

the equation for this situation is y=122+45. to solve the equation you would add 45 and 122 to get a total of 167lbs. in conclusion, grace's weight eight weeks ago was 167lbs.  

the correct answer is 5 6 and 7