How do I solve this equation using the substitution method? They want me to isolate x in the first equation.

x + 3y = - 5

4x - y = - 33

Step-by-step explanation:

X+3y = - 5

4x-y = - 33

1. X=-3y-5 (move the variable to the other side of the equation)

2. 4 (-3y-5) - y = - 33 (substitute the value of x)

3. - 12y-20-y = - 33 (cross multiply)

4. - 13y-20 = - 33 (reduce)

5. - 13y = - 33+20 (isolate variable)

6. - 13y = 13 (addition or subtraction)

7. Y = 13: (-13) (divide)

8. Y = - 1

9. X+3 (-1) = - 5 (substitute value into other equation)

10. X-3 = - 5 (multiply)

11. X = - 5+3 (move to the other side)

12. X = - 2 Y = - 1