Step-by-step explanation:
(n-2)×180=3420
180n-360=3420
180n=3420+360
180n=3780
n=3780/180
n=21
that is, the number of sides is 21
to get the size of each exterior angle=
360/21
=17.14°
Answer:
B & C
Step-by-step explanation:
The two binomials are equal to zero to find the roots.
Hope this helps
Answer:
25
Step by step:
1. prepare the equation
-4 = x/5 - 9
2. add 9 to both sides
-4 = x/5 - 9
+9 +9
5 = x/5
3. multiply both sides by 5
5 = x/5
(5) (5)
25 = x
4. x=25
Hope this helps
Answer:
Amount each friend pays for the gift = $20
Step-by-step explanation:
Market price of a gift = $70
The store manager takes $10 off the market price.
Marked down amount = $10
New cost price = Marked price - Marked down amount 
The cost of the gift is divided among three friends.
This means that the cost of gift which is $60 is divided by three to get each one's contribution in the gift.
∴ Amount each friend pays for the gift 
(7 × 10-21) / (<span> 7.6 × 10-22) = 9.21 times greater</span>