Question

Usando o método da adição,resolva os sistemas de equações do 1 graua] x+y=43 x-y=29b] x+y=3,8 x-y=1,4c]4x+y=33 -4x+5y=-51 d]7x+2y=-31 10x+2y=-46e]5x-4y=20 2x+3y=8

Answer 1

Boa tarde

a]

x+y=43
x-y=29
2x = 72
x = 36
36 + y = 43
y = 7

b]

x+y=3,8
x-y=1,4
2x = 5,2
x = 2.6
2.6 + y = 3.8
y = 1.2

c]

4x+y=33
-4x+5y=-51
6y = 18 
y = 3
4x + 3 = 33
4x = 30
x = 15/2

d]

7x+2y=-31
10x+2y=-46
3x = -15
x = -5
-35 + 2y = -31
2y = 4
y = 2

e]

5x-4y=20
2x+3y=8
15x - 12y = 60
  8x + 12y = 32
23x = 92
x = 4
20 - 4y = 20
y = 0 

Answer 2

Olá boa tarde!

a)

$x+y=43$
$x-y=29$
$2x = 72$
$x = 36$
$36 + y = 43$
$y = 7$

b)

$x+y=3,8$
$x-y=1,4$
$2x = 5,2$
$x = 2.6$
$2*6 + y = 3*8$
$y = 1.2$

c)

$4x+y=33$
$-4x+5y=-51$
$6y = 18$
$y=3$
$4x+3=33$
$4x=30$
$x =\frac{15}{2}$

d)

$7x+2y=-31$
$10x+2y=-46$
$3x = -15$
$x = -5$
$-35 + 2y = -31$
$2y = 4$
$y = 2$

e)

$5x-4y=20$
$2x+3y=8$
$15x-12y=60$
$8x+12y=32$
$23x=92$
$x=4$
$20-4y=20$
$y=0$