Step-by-step explanation: For this problem lets have t be equal to the original temperature in the beginning of the day. The equation -9 + 21 = t represents this situation because it states that if we add the degrees that dropped to the current degrees it will give us our original degrees.

Solve.

-9 + 21 = t (Simply add -9 + 21) -9 + 21 = (+12)

12 = t

So, the original degrees in the beginning of the day was 12°C.

3 0

3 years ago

in the given figure ABIICD . prove that angle BPO + angle POQ + angle DOQ = 4 right angles. 360 degrees

GuDViN [60]

Yes doqpuz shgwz2727819

5 0

3 years ago

R varies directly as s. Find r when s=4 and k=2

lesya692 [45]

$\bf \begin{array}{cccccclllll}
\textit{something}&&\textit{varies directly to}&&\textit{something else}\\ \quad \\
\textit{something}&=&{{ \textit{some value}}}&\cdot &\textit{something else}\\ \quad \\
y&=&{{ k}}&\cdot&x
\\
&& y={{ k }}x
\end{array}\\\\
-------------------------------\\\\
thus\implies r=ks\qquad 
\begin{cases}
k=2\\
\uparrow \\
constant\ of\\
variation\\
s=4
\end{cases}\implies r=2\cdot 4$

5 0

3 years ago

A convex polyhedron has (4a) faces, (6a) vertices, and (8a + 2) edges. What is the value of a?

Snowcat [4.5K]

V + F = E + 2
Plugging in the given values:-

6a + 4a = 8a + 2 + 2

10a - 8a = 4
2a = 4
a = 2

4 0

3 years ago

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HELP PLEASEEEE!! First correct answer gets brainliest ! ​

HELP PLEASEEEE!! First correct answer gets brainliest !