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2 years ago

1 y = 3x - 4 2 x + y = 8 use the method of substitution

Mathematics

1 answer:

Charra [1.4K]2 years ago

5 0

Answer:

x = 2.4; y = 3.2

Step-by-step explanation:

y = 3x - 4

2x + y = 8

2x + 3x - 4 = 8

5x - 4 = 8

5x = 12

x = 12 / 5

x = 2.4

y = 3(2.4) - 4

y = 7.2 - 4

y = 3.2

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Two fractions are given. For each one, write its decimal equivalent and determine if the decimal is terminating or non terminati

ziro4ka [17]

Answer:

9/20 yes, 4/15 not. See below

Step-by-step explanation:

Pick 9/20 and multiply numerator and denominator by 5:

9/20 = 45/100

We know that if we divide a number by 100 we need to move the coma as two places left, so:

9/20 = 45/100 = 0.45

And this is a terminal decimal as we know where it ends.

On the other hand if we pick 4/15 let try to divide it (here I will do it 'manually'):

4 |_ 15

we can divide 4 by 15, so we use 40 and begin with a comma

40 |_ 15

15 enters 2 times in 40 with a rest of 10, so:

40 |_ 15

30 0.2

100

100 divided by 15 is 6 and we have 10 as rest again, and again and again...

40 |_ 15

30 0.266.....

100

....

So, we will have 0.266666666666666 infinitely. The decimal for 4/15 is non terminating and is 0.26666666666666666...

6 0

3 years ago

Help me with these simple math problems

earnstyle [38]

Answer:

Please read the answer below.

Step-by-step explanation:

1. Australia:

75 * 1.87 =140 Australian dollars

2. Brazil:

75 * 2.32 = 174 Reals

3. Britain:

75 * 0.69 = 52 Pounds

4. Canada:

75 * 1.60 = 120 Canadian dollars

5. China:

75 * 8.28 = 621 Yuan

6. Denmark:

75 * 8.43 = 632 Kroner

7. Japan:

75 * 131.55 = 9,866 Yen

8. Mexico:

75 * 9.19 = 689 Mexican pesos

9. South Africa:

75 * 11.9 = 893 Rands

10. Sweden:

75 * 10.61 = 796 Kronor

11. Switzerland:

75 * 1.68 = 126 Francs

12. Thailand:

75 * 44.18 = 3,314 Baht

All currencies rounded to the next integer.

Note: Same answer to question 14454918, answered by me today.

8 0

3 years ago

Help please. Please gets this right.

Bas_tet [7]

Answer:

y=-3/2x

Step-by-step explanation:

4 0

3 years ago

Whatis the value of x in the equation x - y = 30, when y = 15? 8

Ostrovityanka [42]

Answer:

x=45

Step-by-step explanation:

30+15=45

4 0

3 years ago

One member of the debate team is going to be chosen president. each member is equally likely to be chosen. the probability that

inessss [21]

Let
x-------> the probability that a boy is chosen
B------> number of boys in the debate team
G------> number of girls in the debate team

we know that
B+G=20-----> G=20-B-----> equation 1
probability that a boy is chosen=number of boys in the debate team/total of people
so
x=B/20-------> equation 2

the probability that a girl is chosen is 2/3 the probability that a boy is chosen
probability that a girl is chosen=(2/3)*x
probability that a girl is chosen=G/20
(2/3)*x=G/20-----> equation 3
substitute equation 1 in equation 3
(2/3)*x=[20-B]/20----> equation 4

resolve the equations system
x=B/20
(2/3)*x=[20-B]/20

using a graph tool
see the attached figure
the solution is
x=0.6
B=12
G=20-12-----> G=8

number of boys in the debate team is 12
number of girls in the debate team is 8
the probability that a boy is chosen is 0.6 ----> 60%
the probability that a girl is chosen is 0.6*(2/3)----> 0.4---> 40%

the answer is
number of girls in the debate team is 8

7 0

3 years ago