Solve each systems of equations by eliminating
x-2y=10
x-3y=5

2x-3y=9
-5x-3y=30

x+y=-4
x-y=2

y = 5

x = 20

x = -3

y = -5

x = -1

y = -3

Step-by-step explanation:

The first set of simultaneous equations.

x = 20 and y = 5

The second set of simultaneous equations:

x = -3 and y = -5

The third set of simultaneous equations:

x = -1 and y = -3

Step-by-step explanation:

The first set of simultaneous equations.

x - 2y = 10 ... (i)

x - 3y = 5 ... (ii)

Subtracting (i) - (ii) we get;

0 + y = 5

Hence y = 5 and,

x - 2(5) = 10

x = 10 + 10 = 20

The second set of simultaneous equations:

2x - 3y = 9 ... (i)

-5x - 3y = 30 ... (ii)

Subtracting (i) - (ii) we get;

7x + 0 = -21

7x = -21

x = -3

and,

2(-3)  - 3y = 9

3y = -6 - 9

3y = -15

y = -5

The third set of simultaneous equations:

x + y = -4 ... (i)

x - y = 2 ... (ii)

Adding (i) - (ii) we get;

2x + 0 = -2

2x = -2

x = -1

and,

-1 - y = 2

y = -1 - 2 = -3