The solution is (-1, -1)
Step-by-step explanation:
3x - 2y = -1 ...equation 1
y = 5x + 4 ...equation 2
In equation 2, y has been made the subject of formula
So, we can substitute 5x + 4 for y in equation 1:
3x - 2(5x + 4) = -1
expanding the parenthesis:
3x - 10x - 8 = -1
-7x - 8 = -1
add 8 to both sides:
-7x - 8 + 8 = -1 + 8
-7x = 7
divide both sides by -7:
-7x/-7 = 7/-7
x = -1
substitute 7 for x in equation 2:
y = 5(-1) + 4
y = -5 + 4
y = -1
The solution (x, y) = (-1, -1)