Question

Ayúdenme a resolver los siguientes sistemas de ecuaciones porfa!!!
2x-8=2. x=-4y
2m+n=4. m-2n=7
5x+3y=425. 3x+3y=309

Answer 1

a)
2x - 8 = 2
2x = 2+8
2x = 10
x = 10/2
x = 5

x = -4y
5 = -4y
5/-4 = y

comprobación :
x = -4y
5 = -4(5/-4)
5 = (-4*5/4)
5 = -20/-4
5 = 5


b)
2m+n= 4
(-2) m-2n = 7
----------------
2m + n = 4
-2m + 4n = -14
--------------------
5n = -10
n = -10/5
n = -5

2m+n = 4
2m -5 = 4
2m = 4+5
m = 9/2

comprobación:
2m + n = 4
2*9/2 + (-5) = 4
18/2 -5 = 4
9 -5 = 4
4 = 4


c)
5x + 3y = 425
(-1) 3x + 3y = 309
-------------------------
5x + 3y = 425
-3x -3y = -309
-----------------------
2x = 116
x = 116/2
x = 58

5x + 3y = 425
5(58) + 3y = 425
290 + 3y = 425
3y = 425-290
3y = 135
y = 135/3
y = 45


comprobación :

3x + 3y =309
3(58) + 3(45) = 309
174 + 135 = 309
309 = 309