Answer:
70°
Step-by-step explanation:
A right angle is 90°. 90°-20°=70°
Answer:
x
=
2
±
√
7
Explanation:
there are no whole numbers which multiply to - 3
and sum to - 4
we can solve using the method of
completing the square
the coefficient of the
x
2
term is 1
∙
add subtract
(
1
2
coefficient of the x-term
)
2 to
x2
−
4
x
⇒
x
2
+2(−
2
)
x
+
4
−
4
−
3
=
0
⇒
(
x
−
2
)2
−
7
=0
⇒
(
x
−
2
)
2
=
7
take the square root of both sides
⇒
x
−
2
=
±
√
7
←
note plus or minus
⇒
x
=
2
±
√
7←
exact solutions
Answer:
i. 9
ii. 14
iii. 405
iv. 
Step-by-step explanation:
The number of diagonals in a polygon of n sides can be determined by:

where n is the number of its sides.
i. For a hexagon which has 6 sides,
number of diagonals = 
= 
= 9
The number of diagonals in a hexagon is 9.
ii. For a heptagon which has 7 sides,
number of diagonals = 
= 
= 14
The number of diagonals in a heptagon is 14.
iii. For a 30-gon;
number of diagonals = 
= 
= 405
The number of diagonals in a 30-gon is 405.
iv. For a n-gon,
number of diagonals = 
The number of diagonals in a n-gon is 
Answer:
x = 21/2
Step-by-step explanation:
Step 1: Write equation
-4(3/2x - 12) = -15
Step 2: Solve for <em>x</em>
- Distribute -4: -6x + 48 = -15
- Subtract 48 on both sides: -6x = -63
- Divide both sides by -6: x = 21/2
Answer:
because it doesn't have an equal sign.
Step-by-step explanation: