Respuesta :
Answer:
6 , 2 , 5 , 7 , 4 , 1 , 3
Step by Step:
1) x - 3(10 - 2x) = -2
x - 30 + 6x = -2
7x - 30 = -2
7x = 28
x = 4
2) x + 2(4 - 2x) = 5
x + 8 - 4x = 5
-3x + 8 = 5
-3x = -3
x = 1
3) 5(18 - 4y) + y = 33
90 - 20y + y = 33
90 - 19y = 33
-19y = -57
y = 3
x = 18 - 4(3)
x = 18 - 12
x = 6
4) 8x + 4(13 - 2x) = 52
8x + 52 - 8x = 52
52 = 52
5) x + 3(-11 + 6x) = 5
x - 33 + 18x = 5
19x - 33 = 5
19x = 38
x = 2
6) -6(5 - 2y) - 3y = -2
-30 + 12y - 3y = -2
-30 + 9y = -2
9y = 28
y = 3
2x + 3(3) = 5
2x + 9 = 5
2x = -4
x = -2
7) 2x + 3(10+x) = 45
2x + 30 + 3x = 45
5x + 30 = 45
5x = 15
x = 3
Answer:
The order for the systems is 2), 5),7), 1) and 3)
Step-by-step explanation:
To find the solution for ecah system first you have to choose a method, for example you can isolate one of the variables (x or y) in both equations and then equal each other.
1) 2x + y = 10 ⇒ y= 10 - 2x
x - 3y = -2 ⇒ -3y = -2 - x ⇒ y = (-2 - x)/-3 ⇒ y = 2/3 + (1/3)x
Now you have to equal both equations
10 - 2x = 2/3 + (1/3)x ⇒ 10 - 2/3 = (1/3)x + 2x ⇒28/3 = (7/3)x
⇒ (28/3)/(7/3) = x ⇒ 4.
With the "x" value obtained we return to the original equations and replace it there to find "y".
2x + y = 10 ⇒ 2(4) + y = 10 ⇒ y= 10 - 8 ⇒ y =2
The solution to the system is (4,2).
If you do the same for all the systems you will find that the solutions are
2) x + 2y = 5
2x + y = 4
Solution = (1, 2)
3) 5x + y = 33
x = 18 − 4y
Solution = (6,3 )
4) y = 13 − 2x
8x + 4y = 52
Solution = ∅, no solution
5) x + 3y = 5
6x − y = 11
Solution = (2, 1)
6) 2x + y = 10
-6x − 3y = -2
Solution = ∅, no solution.
7) y = 10 + x
2x + 3y = 45
Solution = (3, 13)