Question

Homework Help ASAP. 5 Problems!

Answer 1

"Solve each system using elimination. Tell whether the system has one solution, infinitely solutions, or no solution."
#19. x-3y=-7
2x=6y-14

#20. 3x-5y=-2
x+3y=4

#21. x+2y=6
2x-4y=-12

#22. 5x+y=15
3y=-15x+6

#24. 3x-y=-2
-2x+2y=8

HELP. THIS IS DUE TOMORROW.!.

Answer 2

3x-5y=-2 <-- Multiply by 3
x+3y=4 <---Multiply by 5

9x-15y=-6
5x+15y=20
------------
14x =14

Then, 14x=14, x=1

Do you see how I got that? :o)

Answer 3

19. x - 3y = -7
2x = 6y - 14 -->2x - 6y = - 14
---------------
now your problem reads....
x - 3y = -7 -->(-2)x - 3y = -7
2x - 6y = -14
---------------
-2x + 6y = 14 (result of multiplying by -2)
2x - 6y = -14
-------------
this has no solution

20. 3x - 5y = -2
x + 3y = 4 --->(-3)x + 3y = 4
----------------
3x - 5y = -2
-3x - 9y = - 12 (result of multiplying by -3)
---------------add
-14y = -14 (divide by -14 to get y by itself)
-14y/-14 = -14/-14
y = 1

now sub 14 in for y in either of original equations...
x + 3y = 4
x + 3(1) = 4
x + 3 = 4
x = 4 - 3
x = 1

check...
x + 3y = 4
1 + 3(1) = 4
4 = 4 (correct)

one solution (1,1) ---> x = 1 and y = 1

now you see how it is done....see what you can do

Answer 4

I was wrong about # 19....it has infinite solutions....sorry about that.