Answer: x = - 5
y = 0
Step-by-step explanation:
The given system of equations is expressed as
- 4x + 7y = 20 - - - - - - - - - - - -1
y = 3x + 15 - - - - - - - - - - - - - - 2
We would apply the method of substitution by substituting equation 2 into equation 1, it becomes
- 4x + 7(3x + 15) = 20
- 4x + 21x + 105 = 20
17x + 105 = 20
Subtracting 105 from the left hand side and the right hand side of the equation, it becomes
17x + 105 - 105 = 20 - 105
17x = - 85
x = - 85/17
x = - 5
Substituting x = - 5 into equation 2, it becomes
y = 3 × - 5 + 15
y = - 15 + 15
y = 0
