Question

Solve 5 medals
3x - 5y = 17
9x - 15y = -4

Answer 1

Multiply the top by -3 to solve by elimination.
You get
-9x + 15y = -51
9x + 15y = -4
\[\Huge 0 \ne -51\]
no solution

Answer 2

how do you know when you have to add both x and y termns?

Answer 3

Oops the second equation is 9x - 15 y = -4 *
Well you have common terms in both equations..
3x and 9x
both are factors of 3. for example.

Answer 4

you can cancel x out by multiplying the top out by multiplying the equation by -3.
but this also cancels out the y term

Answer 5

Something like
3x + 5y = 0
-3x - 5y = 0
0 = 0
this would mean infinite solutions
in this case
0 is not equal to -51, so there is no solution

Answer 6

5x + 2y = 7
10x + 4y = 14
---------------
15x + 6y = 21
-15 15
---------------
6y=6?

Answer 7

did i do this one right?

Answer 8

No, you have two variables.
you cant just get rid of x by -15..

Answer 9

so there's no solution?

Answer 10

Divide the second equation by -2
you get
5x + 2y = 7
-5x -2y = -7
add the equations
0 = 0
this system has infinite solutions

Answer 11

What is the value of y in the solution to the following system of equations?
5x - 3y = -3
2x - 6y = -6

Answer 12

so here what would i do?

Answer 13

Get rid of x.
Multiply the top equation by 2
and the bottom by -5
2(5x-3y = -3)
-5(2x-6y = -6)
10x - 6y = -6
-10x + 30y = 30
add
24y = 24
y = 1

Answer 14

Use the substitution method to solve the following system of equations.
3x + 5y = 3
x + 2y = 0

Answer 15

so here i would add
3x+5y=3
x+2y=0
----------
4x+7y=3