this is a system of equations.
eliminating method:
1) move the 3y to the other side so it looks like the second equation.
5x - 3y = 18
3x + 5y = 4
2) multiply both of the equations by a number to make the equations eliminate one of the variables.
5(5x - 3y = 18) —> 25x - 15y = 90
3(3x + 5y = 4) —> 9x + 15y = 12
3) subtract the two equations (the y’s crossed out) and solve for x:
16x = 78
16x/16 = 78/16
x = 4.875 ≈ 4.9 ≈ 5
4) plug x into one of the two equations (preferably the easier one) to solve for y:
5(4.875) - 3y = 4
24.375 - 3y = 4
-3y = -20.375
-3y/3 = -20.375/-3
y = 6.791667 ≈ 6.8 ≈ 7
answers: x = 4.9 / y = 6.8