Solve the simultaneous equation

4x+7y=1

3x+10y=15

4x + 7y = 1 ⇒ 12x + 21y = 3

3x + 10y = 15 ⇒ 12x + 40y = 60

-19y = - 57

-19 - 19

y = 3

4x + 7 (3) = 1

4x + 21 = 1

- 21 - 21

4x = - 20

4 4

x = - 5

(x, y) = (-5, 3)

4x + 7y = 1

3x + 10y = 15

Multiply the first equation by - 3, and the 2nd by 4.

-12x - 21y = - 3

12x + 40y = 60

Add the equations:

19y = 57

y = 3

Plug this into any of the two equations to find 'x':

4x + 7y = 1

4x + 7 (3) = 1

4x + 21 = 1

Subtract 21 to both sides:

4x = - 20

Divide 4 to both sides:

x = - 5

So our solution is (-5, 3)