Question

Calcule:
1)x=3 + 12.t + 2.t2
t=1 ; t=3
x=? x=?

t=6 ; t=9
x=? x=?

x= -15
t=?
2)x= -2 +4.t
t=9 ; t=15 ; t=20
x=? x=? x=?
x=3 ; x=4
t=? t=?
Me AJUDEM pfvr urgente.

Answer 1

1)x=   $3 + 12.t + 2.t^{2}$

t=1  → Onde tiver t você vai substituir pelo numero que foi dado

Assim...

$3+12*(1)+2*(1)^{2}$

$3+12+2*1\\3+12+2\\17$

x=17

__________//______________

t=3

$3 + 12.t + 2.t^{2}$

$3+12*(3)+2*(3)^{2} \\3+ 36 +2*9\\3+36+18\\57$

x=57

__________//______________

t=6

$3 + 12.t + 2.t^{2}$

$3+12*(6)+2*(6)^{2} \\3+72+2*36\\3+72+72\\147$

x=147

__________//__________________

t=9

$3 + 12.t + 2.t^{2}$

$3+12*(9)+2*(9)^{2} \\3+108+2*81\\3+108+162\\273$

x=273

___________//_____________________

x=-15

$x=3+12.t+2.t^{2} \\-15=3+12.t+2.t^{2}\\2.t^{2}+12.t+3+15=0$

$2t^{2}+12t+18=0$

Fazendo o Delta...

a=2         b=12        c=18

Δ=$b^{2} -4*a*c$

Δ=$12^{2}-4*2*18$

Δ=$144-4*2*18$

Δ=$144-144$

Δ=$0$

x= -b±√Δ  / 2.a

$x= \frac{-12 +-\sqrt{0} }{2*2} \\\\x^{1} = \frac{-12}{4} = -3\\x^{2} = \frac{-12}{4} = -3$

_____________________________________________

2)x= $-2+4t$

t=9

x= -2+4*9

x= -2+36

x=34

_______________

t=15

x= -2+4*15

x= -2+60

x=58

_______________

t=20

x= -2+4*20

x= -2+80

x=78

_________________

x=3

3= -2+4*t

3+2= 4*t

5=4*t

5/4 =t

_________________

x=4

4= -2+4*t

4+2= 4*t

6=4*t

6/4 =t

Simplificando....

3/2=t

Bons estudos :)