2x - 3y = -24
x+ 6y = 18
you solve the first one by the x:
2x = -24 + 3y
x = (-24+3y)/2
then you substitute what you found in the other equation and you solve by y
(-24+3y)/2 + 6y = 18 multiply everything by 2
-24 + 3y + 12y = 36
3y + 12y = 36 + 24
15y = 60
y = 60/15
y = 4
Good job! You found your y! :D
Now let's substitute the y in the first equation with 4:
2x - 3(4) = -24
2x - 12 = -24
2x = -24 + 12
2x = -12
x = -12/2
x= -6
Done!! ;) <span />
Answer:
A math teacher
Step-by-step explanation:
Answer:
The average is around 75.5
Step-by-step explanation:
Answer:
Step-by-step explanation:
3x – y + 2z = 6 - - - - - - - - - 1
-x + y = 2 - - - - - - - - - - - - -2
x – 2z = -5 - - - - - - - - - - - -3
From equation 2, x = y - 2
From equation 3, x = 2z - 5
Substituting x = y - 2 and x = 2z - 5 into equation 1, it becomes
3(y - 2) – y + 2z = 6
3y - 6 - y + 2z = 6
3y - y + 2z = 6 + 6
2y + 2z = 12 - - - - - - - - - 4
3(2z - 5) – y + 2z = 6
6z - 15 - y + 2z = 6
- y + 6z + 2z = 6 + 15
- y + 8z = 21 - - - - - - - - - - 5
Multiplying equation 4 by 1 and equation 5 by 2, it becomes
2y + 2z = 12
- 2y + 16z = 42
Adding both equations
18z = 54
z = 54/18 = 3
Substituting z = 3 into equation 5, it becomes
- y + 8×3 = 21
- y + 24 = 21
- y = 21 - 24 = - 3
y = 3
Substituting y = 3 into equation 2, it becomes
-x + 3 = 2
- x = 2 - 3 = -1
x = 1
