Sagot :
Answer:
x = 3, y = - 9
Step-by-step explanation:
5x + 5y = - 30...... (1)
2x - y = 15
-y = 15 - 2x
y = 2x - 15..... (2)
From equations (1) & (2)
5x + 5(2x - 15) = - 30
5x + 10x - 75 = - 30
15x = 75 - 30
15x = 45
x = 45/15
x = 3
Plug x = 3 in equation (2)
y = 2*3 - 15
y = 6 - 15
y = - 9
Therefore,
x = 3, y = - 9
or
(x, y) = (3, - 9)
5x + 5y = -30
Divide through by 5
X + Y = -6
Multiplying the equation by 2 and the equation 2x - y = 15 by 1 in order to get rid of x
2x + 2y = -12
2x - y = -15
Subtracting both equations
3y=3
y=1
Substituting y = 1 to get x in any equation
Using 2x - y = -15
2x - 1 = -15
2x =-15 + 1
2x = -14
x = -14/2
x = -7
Divide through by 5
X + Y = -6
Multiplying the equation by 2 and the equation 2x - y = 15 by 1 in order to get rid of x
2x + 2y = -12
2x - y = -15
Subtracting both equations
3y=3
y=1
Substituting y = 1 to get x in any equation
Using 2x - y = -15
2x - 1 = -15
2x =-15 + 1
2x = -14
x = -14/2
x = -7