Question

5 x – 4 y = 14 3 x + 7 y = - 1

Answer 1

x = 2 and y = -1

Explanation:

5x - 4y = 14 (call this equation no. 1)

3x + 7y = -1 (call this equation no. 2)

multiply all of equation no. 1 by 3.

this gives 15x -12y = 42 (call this equation no. 3)

multiply all of equation no. 2 by 5

this gives 15x + 35y = -5 (call this equation no. 4)

subtract no. 4 from no. 3

0x + (-12 - 35)y = 42 - (-5)

-47y = 42 + 5 = 47

y = - 1

now input y =-1 into equation no. 1.

5x - 4(-1) = 14

5x = 14 + 4(-1)

5x = 14 - 4 = 10

x =2

input y= -1 and x = 2 into equation no. 2 to confirm they are correct

3x + 7y = -1

3(2) + 7(-1) = -1

6 - 7 = -1

so, x = 2 and y = -1