Hard mathematical questions? See if you are smart enough.?

Question

I will give the answers at the end.

Multiply one equation by a number before adding or subtracting. Solve the two equations. Show working so I know you are not just asking anyone else.

3x + 2y = 12
2x + 7 = 7

5x - y = 17
2x + 3y = 0

Answer 1

lol hard?? thats like algebra 2

Answer 2

5x - y = 17- - - - - - - Equation 1
2x + 3y = 0- - - - - -- Equation 2
- - - - - - - - - -

Substitute method equation 1

5x - y = 17

5x - y - 5x = - 5x + 17

- y = - 5x + 17

-1(- y = - 1(- 5x) + (- 1)(17

y = 5x + (- 17)

y = 5x - 17

Insert the y value into equation 2

- - - - - - - - - - - - - - - - - - - - - - - - -

2x + 3y = 0

2x + 3(5x - 17) = 0

2x + 15x - 51 = 0

17x -51 = 0

17x - 51 + 51 = 0 + 51

17x = 51

17x / 17 = 51 / 17

x = 51 / 17

x = 3

Insert the x value into equation 1

- - - - - - - - - - - - - - - - - - - - - - - - -

5x - y = 17

5(3) - y = 17

15 - y = 17

15 - y - 15 = 17 - 15

- y = 2

- 1( - y) = - 1 (2)

y = - 2

Insert the y value into euation 1

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Check for equation 1

5x - y = 17

5(3) - (- 2) = 17

15 + 2 = 17

17 = 17

- - - - - - - - -

Check for equation 2

2x + 3y = 0

2(3) + 3(-2) = 0

6 + ( - 6) = 0

6 - 6 = 0

0 = 0

- - - - - - - - -

The solution set { 3, -2 }

- - - - - - - - -s-

Answer 3

First one...multiply the first equation by 2 and the third by -3...is it 7y or y in the second ec?

The second one is a lot easier...multiply the first ec by 3 and add the 2...the result is 17x=51 so x=3 y= -2

Answer 4

I don't understand your directions, do you mean, solve them like systems of linear equations?

like:

2x + 7=7
-7 -7

2x=0
x=0

3(0) + 2y= 12

2y=12
y=6

(0,6)

????

Answer 5

The answer is 3. I hope nobody falls for this crap. Do your own homework.