All categories

3 years ago

Solve the following pair of simultaneous equation using elimination method.

Mathematics

1 answer:

sp2606 [1]3 years ago

3 0

Answer:

x = 1 and y = −2

Step-by-step explanation:

Rewrite equations:

x + 2y = −3

3x − 2y = 7

Step 1: Solve x+2y=−3 for x:

x + 2y = −3

x + 2y + −2y = −3 + −2y (Add -2y to both sides)

x = −2y − 3

Step 2: Substitute −2y − 3 for x in 3x − 2y = 7:

3x − 2y = 7

3(−2y − 3) − 2y = 7

−8y − 9 = 7 (Simplify both sides of the equation)

−8y − 9 + 9 = 7 + 9 (Add 9 to both sides)

−8y = 16

−8y/−8 = 16/−8 (Divide both sides by -8)

y = −2

Step 3: Substitute −2 for y in x = −2y − 3:

x = −2y − 3

x = (−2)(−2) − 3

x = 1 (Simplify both sides of the equation)

You might be interested in

Betsy is saying for a bird cage. She saves $1 the first week, $3 the second week, $9 the third week, and so on. All together how

Zigmanuir [339]

Answer:

Betsy will save $121 in 5 weeks.

Step-by-step explanation:

We can see that Betsy's savings are 3 times the saving of her last week. We can see that this is an geometric sequence as 1,3,9,..

To find the sum of our geometric sequence we will use $S_{n}=a\cdot \frac{1-r^{n}}{1-r}$ , where n is number of terms we are taking sum of, a is first term of sequence and r is common ratio of the sequence.

$S_{5}=1\cdot \frac{1-3^{5}}{1-3}$

$S_{5}=\frac{1-243}{-2}$

$S_{n}=\frac{-242}{-2}=121$

Therefore, Betsy will save $121 in 5 weeks.

8 0

3 years ago

SCORPION-xisa [38]

$\qquad \qquad \textit{inverse proportional variation} \\\\ \textit{\underline{y} varies inversely with \underline{x}} ~\hspace{6em} \stackrel{\textit{constant of variation}}{y=\cfrac{\stackrel{\downarrow }{k}}{x}~\hfill } \\\\ \textit{\underline{x} varies inversely with }\underline{z^5} ~\hspace{5.5em} \stackrel{\textit{constant of variation}}{x=\cfrac{\stackrel{\downarrow }{k}}{z^5}~\hfill } \\\\[-0.35em] \rule{34em}{0.25pt}$

$\stackrel{\textit{"F" inversely proportional to }\sqrt{g}}{F=\cfrac{k}{\sqrt{g}}}\qquad \textit{we also know that} \begin{cases} F=18\\ g=9 \end{cases} \\\\\\ 18=\cfrac{k}{\sqrt{9}}\implies 18=\cfrac{k}{3}\implies 54=k~\hfill\boxed{ F=\cfrac{54}{\sqrt{g}}} \\\\\\ \textit{when g = 36, what is "F"?}\qquad F=\cfrac{54}{\sqrt{36}}\implies F=\cfrac{54}{6}\implies F=9$

3 0

2 years ago

On August 20, 1989, in Cologne, West Germany, Said Aouita of Morocco also established a world record when he ran the 3000. m run

zalisa [80]

Answer:

Average speed of Aouita = 6.68 meter per second.

Step-by-step explanation:

To create a world record Aouita ran a distance = 3000 m

He took the time to cover this distance = 7 minutes 29.45 seconds

= (7×60) + 29.45 seconds

= 449.45 seconds

Since, formula for the average speed is given by,

Average speed = $\frac{\text{Total distance covered}}{\text{Total time taken}}$

Therefor, average speed of Aouita = $\frac{3000}{449.45}$

= 6.675

≈ 6.68 meter per second

Average speed of Aouita was 6.68 meter per second.

8 0

3 years ago

Idenify the names of the countries not labeled on the map

Rus_ich [418]

We cannot answer without the map

7 0

3 years ago

How do I solve 5/6(3/8-x)=16

Diano4ka-milaya [45]

First, distribute the 5/6:

15/48-5/6x=16

Multiply everything by 48 to get rid of fraction:

15 - 40x = 768

-40x = 768

x= -19 1/5

7 0

3 years ago