(50 ) mrs. julien’s and mrs. castillejo’s classes are selling cookie dough for a school fundraiser. customers can buy packages of macadamia nut chip cookie dough and packages of triple chocolate cookie dough. mrs. julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $221.25. mrs. castillejo’s class sold 5 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $191.25. (a) write the system of equations that model the problem. be sure to explain which equation represents which situation. (b) find the cost of each type of cookie. show your work. (c) explain which method you used to solve the system and why you chose that method.

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Step-by-step explanation:

a) Let x and y represent the costs of packages of nut and chocolate dough, respectively. Then the equations describing the sales will be ...

  25x +30y = 221.25

  5x +45y = 191.25

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b) The costs of the packages of dough are ...

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c) A graphing calculator was used to solve the system. The work is attached. This method was chosen because it is quick and easy.

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Additional comment

Note that for the given values of sales, the prices are not integer numbers of cents. The actual values are (x, y) = (4 17/52, 3 10/13). This is unexpected, and suggests that the problem is not carefully considered. With the prices we computed, the sale values would be $221.35 and $191.30. These don't look like numbers where a typo would be involved.

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10