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Nataliya [291]
4 years ago
14

How to solve 7m + 2n = 21 and 10m + 4n = -10 using substitution. Step by step please and thank you!

Mathematics
1 answer:
ryzh [129]4 years ago
5 0
7m+2n=21
-7m      -7m

<u>2n</u>=<u>21-7m</u> 
2        2

n=<u>21-7m
</u>       2
<u>
</u>10m+4(21-7m/2)= -10
<u />-10m                   -10m

4(21-7m/2)= -10-10m

(84-28m/2)= -10-10m
    x2                x2

84-28m    = -20-20m
+20+28m   +20+28m

<u>104</u> = <u>8m
</u>8         8

m=13

10(13) + 4n = -10
-130              -130

<u>4n</u> = <u>-140
</u>4         4
<u>
</u>n= -35

If anything is unclear please feel free to ask.
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The dot plot shows the numbers of pets that students in a class own
Kisachek [45]

Answer:

5 dots above zero

Step-by-step explanation:

Could the question be The dot plot shows the number of pets owned by the students in Jayod’s class.

The center, or the middle value, of the data set is _____.????

If it is that is the answer.

Hope this helps!! :)

5 0
3 years ago
a rectangle field has an anrea of 40cm^2. if one side of the field is 3m longer than the other side, find the new area of the fi
oksian1 [2.3K]

The area of the field where the length of each side is increased by 10% is 48.4 cm^{2}.

Step-by-step explanation:

The given is,

               A rectangle field has an area of 40 cm^{2}

               If one side of the field is 3 cm longer than the other side

               The length of new area in each side is increased by 10%

Step:1

          Let,

                          b - One side of rectangle

                          l - Other side of rectangle

          From given.

                         l -  b +3

           Formula for area of rectangle,

                   Area, a = lb      

                          40 = ( b+3) × b

                         40 = b^{2} + 3b

           Solving the above the equation,

                          b = 5 cm

                            l = 8 cm

Step:2

          If the area of rectangle increased by 10%,

                            l = 8 + ( 8 × \frac{10}{100} )

                              = 8.8

                           b = 5 + ( 5 × \frac{10}{100} )

                              = 5.5

         Area of rectangle is,

                      a = ( 8.8 × 5.5 )

                        = 48.4 square centimeters

Result:

        The area of the field where the length of each side is increased by 10% is 48.4 cm^{2}, if a rectangle field has an area of 40 square centimeters and one side of the field is 3 cm longer than the other side.

             

5 0
3 years ago
If f(x) = 2x + 1, and<br> g(x) = x - 3, then<br> f(g(x)) = [ ? ]x + [ ]
ad-work [718]

Answer:

First box +2

Second box -5

Step-by-step explanation:

Just an Example,

If f(x) = 2x + 1  and we need f(2) we would replace the x in the function with the number 2 because 2 is the domain of the function , so f(2) would become,

f(2) = 2(2) + 1

f(2) = 4 + 1 = 5

Now the question is what is f(g(x)) in this case the domain of the function is g(x). In simpler words we replace x with the function g(x) so here goes,

f(x)=2x+1\\g(x)=x-3\\f(g(x))=2(x-3)+1\\f(g(x))=2x-6+1\\f(g(x))=2x-5

so,

f(g(x)) = 2x - 5

6 0
3 years ago
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