Question

Metodo da substituição →→→→ A)5x-y=4. 3x-4y=0 (B)3x-y=0. -x+4y=22

Answer 1

a)
{5x-y=4 -> -y=4-5x -> y=-4+5x
{3x-4y=0
3x-4(-4+5x)=0
3x+16-20x=0
17x=-16
x=-16/17

y=4+5*-16/17
y=68/17+-80/17
y=-12/17

S=(-16/17, -12/17)

b)
{3x-y=0 -> -y=-3x -> y=3x
{-x+4y=22
-x+4(3x)=22
-x+12x=22
11x=22
x=22/11
x=2

y=3x
y=3*2
y=6

S=(2,6)