13xy^2-10xy-23=0
you first add the like terms and rewrite and thats how you get the answer
Well each piece of the whole is what made the whole... so in that case each piece is little 1/4's of the whole....
Answer: The answer is 
Step-by-step explanation: Given that a school wants to put on a dance recital. The programs of Middle school dancer will be short of 4 minutes each and programmes of High school performers will be long of 7 minutes each.
Number of middle school dances is "M" and number od high school dances is "H".
Since there cannot be more than 10 dances all together, so fisrt inequality can be written as

Also, the entire recital must take maximum 90 minutes, so the second inequality can be written as

Thus, the pair of inequalities is

See the picture attached to better understand the problem
we know that
A quadrilateral is called Cyclic quadrilateral <span>if its all vertices lie on the circle.
</span><span>The opposite angles of a Cyclic - quadrilateral are supplementary
</span>so
∠A+∠C=180°
and
∠
B
+∠D=180°
therefore
the answer is<span>
C) The sum measure of ∠B and ∠D equals 180°</span>