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4 years ago

Can give more points!!!PLEASE HELP!!!!!

Mathematics

1 answer:

kifflom [539]4 years ago

5 0

Answer:

A. Only Khaled

Step-by-step explanation:

The teachers equation is:

$-10x-7y=5$

$12x-8y=-4$

If a row operation on the teacher's equation results in any of the system of the students' equation then the two systems are equivalent and will have the same solution.

For instance:

Let's maintain the bottom equation and add both equation to replace the top equation:

$-10x+12x-7y-8y=5+-4\\12x-8y=-4$

This results in Khaled's equation:

$2x-15y=1\\12x-8y=-4$

On the other hand we cannot perform a row operation to obtain Miku's equation

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A number consist of 2 digits whose sum is 8, If 8 is subtracted from the number, the digits interchange their place. The number

Novay_Z [31]

Step-by-step explanation:

Let's say the two digit number is 10x + y, where x is the first digit and y is the second digit.

The sum of the digits is 8:

x + y = 8

If 8 is subtracted from the number, the digits switch place.

10x + y − 8 = 10y + x

Simplify the second equation:

9x − 8 = 9y

Substitute from the first equation.

y = 8 − x

9x − 8 = 9 (8 − x)

9x − 8 = 72 − 9x

18x = 80

x = 4.444

There's a problem. x isn't an integer. Are you sure you copied the problem correctly? Perhaps you meant if 18 is subtracted from the number, the digits switch place.

9x − 18 = 9 (8 − x)

9x − 18 = 72 − 9x

18x = 90

x = 5

y = 8 − x

y = 3

So the number is 53.

8 0

3 years ago

Read 2 more answers

Suppose that P(n) is a propositional function. Determine for which improper subset of the domain of n the statement P(n) must be

Alinara [238K]

Answer:

a) P(n) is true for all 'n' in the set ; { 0,2,4,6,8 ….. }

b) P(n) is true for all 'n' in the set ; { 0,1,2,3,4,5 ............ }

Step-by-step explanation:

a) As P(0) is true

we will assume that

P(2) is true
P(4) is true
P(6) is true

this simply means that ; P(n) is true for all 'n' in the set

{ 0,2,4,6,8 ….. }

b) since P(0) and P(1) are true

we will assume that

P( 0+2 ) = P(2) is true

also P(1) and P(2) are true

we will assume that

P(1+2) = P(3) is true

Also from the previous answers it can be seen that P(2) + P(3) is true

we will assume

P(2+2) = P(4) is true

This simply means that P(n) is true for all 'n' in the set

{ 0,1,2,3,4,5 ............ }

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3 years ago

Allen has $10 to spend. He bought a sandwich for

Natasha2012 [34]

Answer:

MY friend the anwser is A I hope this will help plz mark me brainliest

Step-by-step explanation:

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3 years ago

The sum of two numbers is 39 and the difference is 3. What are the numbers?

frosja888 [35]

Answer: 21 & 18

Step-by-step explanation:

Sum of two numbers is 39

Difference is 3

Let the numbers be x & y

X+y=39........equation 1

X-y=3...........equation 2

X=3+y............equation 3

Substitute equation 3 into equation 1

(3+y)+y=39

3+y+y=39

3+2y=39

2y=39-3

2y=36

Y=36/2

Y=18

Substitute for y in equation 2

X-y=3

X-18=3

X=3+18

X=21

The two numbers are 21 & 18

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4 years ago

A student has some $1 and $5 bills in his wallet. He has a total of 14 bills that are worth $34. How many of each type of bil

jeka57 [31]

Solution:

we are given that

A student has some $1 and $5 bills in his wallet.

Let there x $1 bills and y number of $5 bills.

He has a total of 14 bills that are worth $34.

So we can write

$x+y=14$

$x+5y=34$

Now solve these two equations together using substitution as follows

$14-y+5y=34\\
\\
4y=34-14\\
\\
4y=20\\
\\
y=5\\
\\
x=14-y=14-5=9\\$

Hence there are 9 $1 bills and 5 bills are of $5.

5 0

3 years ago