Question

solve the system of equations 7x-3y=20 ,and y=5x-4 find x and y​

Answer 1

Step-by-step explanation:

$= > 7x - 3y = 20 \\ = > 5x - y = 4 \\ = > 15x - 3y = 12 \\ = > 15x - 7x - 3y + 3y = 12 - 20 \\ = > 8x = - 8 \\ = > x = - 1 \\ = > y =5( - 1) - 4 = - 5 - 4 = - 9 \\ = > y = - 9$

Answer 2

Answer:

x=-1 and y=-9

Step-by-step explanation:

7x-3y=20 (y=5x-4)

sub (y=5x-4) in 7x-3y=20

7x-3(5x-4)=20

7x-15x+12=20

-8x+12=20

-8x=20-12

-8x=8

x=-1

now sub (x=-1) in y=5x-4

y=5(-1)-4

y=-5-4

y=-9

Therefore, x=-1;y=-9