I need someone to check these answers ASAP.

Mathematics

1 answer:

Reptile [31]3 years ago

7 0

Alright, 1, 2, and 4 are correct but 3 is not.

The error you made could be hard to notice but it was made. So let's put the equation up, 6x-(2x-9)=-31. Your error occurred when you didn;t distribute the negative sign for (2x-9), if you woud have distributed it then the equation would then be simplified into 6x-2x+9=31. You then add like terms and get 4x+9=31, subtract 9 on both sides and you'll get 4x=22. Divide 4 on both sides to isolate the variable and you get x=5.5

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Consider the following equations:

Dmitry [639]

Answer:

The Answer is: (-2,1)

Step-by-step explanation:

8 0

3 years ago

Please help! Please!!

Elza [17]

You can proceed like this,

650 kb for a pic
and 2200kb for song ( 650 + 1550)

total= 18150 kb and 16 files

so, 650 kb each in both pic and song = 16 * 650= 10400

remaining = 18150-10400 = 7750 , which is contributed by additional 1550 of songs that is
7750/1550 = 5

so, a total of 5 songs and 11 pictures were sold..

hope it helped

8 0

3 years ago

A ball is thrown vertically upwards from the ground. It rises to a height of 10m and then falls and bounces. After each bounce,

Citrus2011 [14]

${\huge{\fcolorbox{yellow}{red}{\orange{\boxed{\boxed{\boxed{\boxed{\underbrace{\overbrace{\mathfrak{\pink{\fcolorbox{green}{blue}{Answer}}}}}}}}}}}}}$

(i)

$\sf{a_n = 20 \times {( \frac{2}{3} )}^{n - 1} }$

(ii)

$\sf S_n = 60 \{1 - { \frac{2}{3}}^{n} \}$

Step-by-step explanation:

$\underline\red{\textsf{Given :-}}$

height of ball (a) = 10m

fraction of height decreases by each bounce (r) = 2/3

$\underline\pink{\textsf{Solution :-}}$

(i) We will use here geometric progression formula to find height an times

${\blue{\sf{a_n = a {r}^{n - 1} }}} \\ \sf{a_n = 20 \times { \frac{2}{3} }^{n - 1} }$

(ii) here we will use the sum formula of geometric progression for finding the total nth impact

$\orange {\sf{S_n = a \times \frac{(1 - {r}^{n} )}{1 - r} }} \\ \sf S_n = 20 \times \frac{1 - ( { \frac{2}{3} })^{n} }{1 - \frac{2}{3} } \\ \sf S_n = 20 \times \frac{1 - {( \frac{2}{3}) }^{n} }{ \frac{1}{3} } \\ \sf S_n = 3 \times 20 \times \{1 - ( { \frac{2}{3}) }^{n} \} \\ \purple{\sf S_n = 60 \{1 - { \frac{2}{3} }^{n} \}}$