MATHEMATICS MIDDLE SCHOOL

My algebra math book has this math problem ---> 4a - 3b = 21.i am supposed to figure out if it is true or false. but the thing is, i do not know how to do this so that i can find out if it is true or not.
PLEASE HELP!!!!!

Answers

Answer 1
Answer:
The value of (4a - 3b) depends on what 'a' and 'b' are.

There are many combinations of 'a' and 'b' that make
(4a - 3b) equal to 21, and a whole bunch of others
that don't.

The equation in your question is not true OR false until you know
what 'a' and 'b' are.  I suspect that right next to this problem in your
math book, it gives you some values for 'a' and 'b'.

Here are a few examples of how to do it:

1).  I tell you that  a=2  and  b=1.
You take those numbers, and write them in place
of 'a' and 'b' in the left side of the equation:

                   4a - 3b

                  4(2) - 3(1)

                    8   -   3  =  5

If  a=2  and  b=1, then the left side of the equation is  5, not 21,
and the equation is false. 

================================

2).  I tell you that  a=5  and  b=4.
You take those numbers, and write them in place
of 'a' and 'b' in the left side of the equation:

                       4a - 3b

                       4(5) - 3(4)

                         20 -  12  =  8

If  a=5  and  b=4, then the left side of the equation is  8, not 21,
and the equation is false. 

=================================

3).  I tell you that  a=6  and  b=1.
You take those numbers, and write them in place
of 'a' and 'b' in the left side of the equation:

                   4a - 3b

                 4(6) - 3(1)

                   24  - 3  =  21

If  a=6  and  b=1, then the left side of the equation is  21,
and the equation is TRUE.

This is not the only possible pair of numbers for 'a' and 'b'
that make the equation true.  There are tons of possibilities.
Look around the question in your book and see if it gives you
values for 'a' and 'b' to test in the equation.

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x + 5y = 100

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x + 100y = 5

5x + y = 100

Answers

5x + y = 100
5(5 lunches) is 25 arbitrary units
amount left after 5 is 75
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Answer:

its D

Step-by-step explanation:

2(3x - 7) - 4(5x - 8) =74

Answers

Answer:

74

Step-by-step explanation:

you already answered youu ;LOLL
Answer to question: x = -4

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Answers

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Answers

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deepest part of a swimming pool is 12 feet deep. The shallowest part is 3 feet deep. What is the ratio of the depth of the deepest part of the pool to the depth of the shallowest part of the pool

Answers

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Shallowest part of the swimming pool = 3 feet deep
Thus the ratio of both swimming pool depth is:
=> 12 : 3
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Answers

we first need to turn every thing into the same unit of measure ment

1 gallon=4 quarts
60 minutes=1hour

7*60=420  420 is how many quarts per hour but we want gallons so we want to divide by 4
420/4=105
105 gallons per hour
so
qt=quart
4 quart=1 gallon
1 quart=1/4 gallon
min=minute
60 minutes in 1 hour
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so 7 quarts=7 times 1/4 gallons=7/4 gallons
1 minute=1 times 1/60 hours=1/60 minutes

7/4 gallons per 1/60 minutes
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we don't really need to divide so multiply the whole thing by (1/60)/(1/60) to clear bottom fraction
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the asnwer is 105 gallons per hour
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