Solve the system using substitution.

3x+5y=15 2x+4y=8

x=10

y=-3

Step-by-step explanation:

3x + 5y = 15 ... eqn. 1

2x + 4y = 8 ... eqn. 2

multiply eqn. 1 by 2 and eqn. 2 by 3

6x + 10y = 30 ... eqn. 3

6x + 12y = 24 ... eqn. 4

0 - 2y = 6

divide both sides by the coefficient of y which is - 2

- 2y = 6

- 2 - 2

y = - 3

Put y = - 3 into eqn. 1

3x + 5 (-3) = 15

3x - 15 = 15

3x = 15 + 15

3x = 30

3 3

x = 10

Therefore X = 10 and Y = - 3