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tatiyna
3 years ago
9

Kira, goran, & joe sent a total of 90 text messages during the weekend. Goran sent 5 fewer messages than Kira. Joe sent 3 ti

mes as many messages as kira. How many messages did they each send
Mathematics
1 answer:
MissTica3 years ago
4 0

Answer:

Kira sent 19 text messages, Goran sent 14  text messages  and Joe sent 57  text messages.

Step-by-step explanation:

Let be "k" the number of text messages that Kira sent during the weekend, "g" the number of text messages that Gora sent during the weekend and "j" the number of text messages that Joe sent during the weekend.

We know know that they sent a total of 90 text messages then:

k+g+j=90

Goran sent 5 fewer messages than Kira. This is:

g=k-5

And Joe sent 3 times as many messages as Kira. Then:

j=3k

The steps to solve this are:

- Substitute the second equation and the third equatio into the first equation  and then solve for "k":

k+(k-5)+(3k)=90\\\\5k-5=90\\\\5k=90+5\\\\k=\frac{95}{5}\\\\k=19

- Substitute this value into the second equation to find "g":

g=19-5=14

- Substitute the value of "k" into the third equation to find "j":

j=3(19)=57

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Irina-Kira [14]

Answer: Yes I agree with Jada. His approach is correct.

Step-by-step explanation: The question requires the student to write an equivalent equation with fewer terms. Nonetheless, this does not prevent applying a mathematically correct approach.

(1) Noah is wrong and the reason is that the initial step is mathematically incorrect. The expression on the right hand side reads 3(4 - 9x), therefore starting with "8 - 3" is very wrong. The right step was to take one side which is 8 and take the other side which is 3(4 - 9x).

(2) Lin is wrong and the reason is that she started inside the parenthesis and this also is mathematically incorrect. The digits inside the parenthesis are "not like terms" and hence calculating 4 - 9x = -5x is very incorrect (the same way you cannot correctly calculate 500 metres minus 200 inches. You must make sure they are both in meters or in inches, that is both must be like terms).

(3) Jada is very correct in using the distributive property and ended up with the only correct solution. The digits on the right hand side of the expression  was solved first and that resulted in -12 + 27x. The reason being that the number outside the parenthesis which is -3, multiplied both digits inside the parenthesis. The minus sign had a major effect, and after simplifying the right hand side the expression now becomes;

8 - 12 + 27x

Since the like terms are 8 and 12, you can simplify further to become

- 4 + 27x OR the expression can be rearranged as 27x - 4

(4) Andre is not correct and the reason is that although he used the distributive property, he made a slight mistake while solving for the right side of the expression. What Andre did was

-3(4 - 9x)

-12 - 27x

Remember that when a negative value multiplies another negative value the answer is positive. Therefore -3 times -9x should have been +27x, just like Jada did as shown above.

From that point onward, his answer would be incorrect.

5 0
3 years ago
Solve 73 make sure to also define the limits in the parts a and b
Aleks04 [339]

73.

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a)

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b)

Since we can't divide by zero, we need to find when:

x^4-2x^2+144=0

But before, we can factor the numerator and the denominator:

\begin{gathered} \frac{3x^2(x^2+x-12)}{x^4-25x^2+144}=\frac{3x^2((x+4)(x-3))}{(x-3)(x-3)(x+4)(x+4)} \\ so: \\ \frac{3x^2}{(x+3)(x-4)} \end{gathered}

Now, we can conclude that the vertical asymptotes are located at:

\begin{gathered} (x+3)(x-4)=0 \\ so: \\ x=-3 \\ x=4 \end{gathered}

so, for x = -3:

\lim_{x\to-3^-}f(x)=\lim_{x\to-3^-}-\frac{162}{x^4-25x^2+144}=-162(-\infty)=\infty\lim_{x\to-3^+}f(x)=\lim_{x\to-3^+}-\frac{162}{x^4-25x^2+144}=-162(\infty)=-\infty

For x = 4:

\lim_{x\to4^-}f(x)=\lim_{n\to4^-}\frac{384}{x^4-25x^2+144}=384(-\infty)=-\infty\lim_{x\to4^-}f(x)=\lim_{n\to4^-}\frac{384}{x^4-25x^2+144}=384(-\infty)=-\infty

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jenyasd209 [6]

Answer:

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Step-by-step explanation:

1) x

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Step-by-step explanation:

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0.483 x 60 = 28.98 so approximately 29 minutes total driving time

7:15 + 29 minutes is 7:44 am she arrived at work

8 0
3 years ago
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