Question

a){2x+y=10
{3x-y=15

b){3x2=7
{2x-3y=8

Answer 1

a)y=0 e x=5
b)3x-2y=7(1) , {2x-3y=8(2)
x=7/3+2y/3
2.(7/3+2y/3) - 3y= 8
(14/3+4y/3) - 3y= 8
m.m.c
14+4y-9y= 24... y=-10/5
y=-2
x= 7/3+ 2.(-2)/3... x=1

Answer 2

A)
2x + y = 10
3x - y = 15  (+)
--------------------
5x = 25
x = 25/5
x = 5

2x + y = 10
2.5 + y = 10
10 + y = 10
y = 10 - 10
y = 0

**************************
3x - 2y = 7  (3)
2x - 3y = 8  (-2)

  9x - 6y = 21
- 4x + 6y = - 16  (+)
-------------------------
5x = 5
x = 5/5
x = 1

3x - 2y = 7
3.1 - 2y = 7
3 - 2y = 7
3 - 7 = 2y
- 4 = 2y
2y = - 4
y = - 4/2
y = - 2