Let's solve your equation step-by-step.
<span><span><span><span>3v</span>+9</span>−<span>8v</span></span>=<span>−31
</span></span>Step 1: Simplify both sides of the equation.
<span><span><span>−<span>5v</span></span>+9</span>=<span>−31
</span></span>Step 2: Subtract 9 from both sides.
<span><span><span><span>−<span>5v</span></span>+9</span>−9</span>=<span><span>−31</span>−9</span></span><span><span>−<span>5v</span></span>=<span>−40
</span></span>Step 3: Divide both sides by -5.
<span><span><span>−<span>5v</span></span><span>−5</span></span>=<span><span>−40</span><span>−5
</span></span></span><span>v=<span>8</span></span>

so
(this is wrong because
)
Answer:
4140
Step-by-step explanation:
The formula for sum of interior angle is (n-2)180
so since the number of side is 25. substitute 25 in place of n
which is (25-2)180. which is 4140
Answer:△DEF is congruent to △D′E′F′ because the rules represent a translation followed by a reflection, which is a sequence of rigid motions.
Step-by-step explanation:
A rigid motion of the plane is a motion which maintain distance.
Translation is a kind of rigid motion used in geometry to trace a function that moves an object a particular distance.
A reflection is also a kind of rigid motion . It is mainly a 'toss' of a shape across the line of reflection.
So,△DEF is mapped to △D′E′F′ using the rule (x,y)→(x,y+1) ( which is a translation.) followed by (x,y)→(x,−y)(which is reflection),therefore it is a sequence of rigid motions.