Question

A)11x+3y=41 x-y=5

B)-x+9y=-12 3x+y=-20

Answer 1

a) 11x+3y=41
x-y=5

x=5+y
11.(5+y)+3y=41
55+11y+3y=41
14y=41-55
14y=14
y=14/14
y=1

x-y=5
x-(1)=5
x=5+1
x=6


b) -x+9y= -12 .(+3)
3x+y= -20
multiplica por (+3)
- 3x+27y= -36
3x+y = -20
_____________
0+28y= -56
y= -56/28
y= -2

3x+y= -20
3x+(-2)= -20
3x=-20+2
3x= -18
x= -18/3
x= -6
Boa tarde, valeu, boa sorte.