buat yg pinter MTK..TOLONG dunk!!!! pleaseee..?

Question

1. himpunan pnyelesaian dari:
8 pangkt (x-1) = 32 pangkt (5+2x)??

2. dr fungsi eksponen f(x)= 2 pangkt 2(x kuadrat-x-2)
harga x yg memenuhi f(x)= 1 adlh???

3. akar2 prsamaan 2(x kuadrad) + 6x = 1
adlh p dan q. nilai dari:
p kuadrt + q kuadrad = ????



tolongiinnn y...
pliiissss...

Anonymous · Accepted Answer

no.3

akar -akar persamaan 2x^2 + 6x - 1 = 0 adalah p dan q

dimana p + q = -b/a = -6/2 = -3  dan  p * q = c/a = -1/2

p^2 + q^2 = (p + q)^2 - 2 * (p * q)

p^2 + q^2 = (-3)^2 - 2(-1/2)

p^2 + q^2 = 9 + 1 

p^2 + q^2 = 10

bebek · Answer

Soal 1:
8^(x - 1) = 32^(5 + 2x)
2^3(x - 1) = 2^5(5 + 2x)
atau :
3(x - 1) = 5(5 + 2x)
3x - 3 = 25 + 10 x
x = - 4

Soal 2:
f(x) = 2^2(x^2 - x - 2)
karena f(x) = 1 = 2^0 , maka :
2^2(x^2 - x - 2) = 2^0
atau:
2(x^2 - x - 2) = 0
x^2 - x - 2 = 0
(x - 2)(x + 1) = 0
x = 2 atau x = - 1

Soal 3:
2x^2 + 6x = 1 => 2x^2 + 6x - 1 = 0
maka :
p + q = - 6/2 = - 3
pq = - 1/2
sehingga :
p^2 + q^2 = [p + q]^2 - 2pq = [- 3]^2 - 2[- 1/2] = 10

semoga membantu

ditto · Answer

setuju..
wah, telat tau soalnya nih..
hehe

81d4d4r1 4n99un · Answer

1. 8^(x-1) = 32^(5+2x)
===> 2^3(x-1) = 2^5(5+2x)
===>3x-3= 25+10x
===>7x =-28
===>x = -28/7 = -4

2.f(x) = 2^2(x^2-x-2)
===>x^2-x-2 = 0
===>(x+1) (x-2) = 0
===>x = -1 dan x = 2

3. 2x^2 + 6x = 1
===>2x^2 + 6x -1 = 0
lihat===>http://www.purplemath.com/modules/quadform.htm

silakan cek lagi yah...maklum dah lama g belajar :D