3x + 5y = 29 first equation
y = -4x - 1 second equation
substitute the second equation to the first equation;
3x + 5(-4x - 1) = 29
-17x - 5 = 29
solve for x;
-17x - 5 = 29
-17x = 34
x = -2
substitute x = -2 into the second equation to find y;
y = -4x - 1
y = -4(-2) - 1
y = 8 - 1
y = 7
so;
x = -2, y = 7
hope this helps, God bless!