Answer: x = - 4
y = 3
Step-by-step explanation:
The given system of simultaneous equations is expressed as
3x+4y=0 - - - - - - - - - - - - -1
2x+5y=7- - - - - - - - - - - - - - - 2
From equation 1, we would make x the subject of the formula. Firstly, we would subtract 4y from the Left hand side and the right hand side of the equation. It becomes
3x +4y - 4y = 0 - 4y
3x = - 4y
We would divide the Left hand side and the right hand side of the equation by 3. It becomes
3x/3 = - 4y/3
x = - 4y/3
Substituting x = - 4y/3 into equation 2, it becomes
2 × - 4y/3 +5y = 7
- 8y/3 + 5y = 7
(- 8y + 15y)/3 = 7
7y/3 = 7
Cross multiplying, it becomes
7y = 21
Dividing the left hand side and the right hand side of the equation by 7, it becomes
7y/7 = 21/7
y = 3
Substituting y = 3 into x = - 4y/3, it becomes
x = - 4× 3/3
x = - 4
