Jika AG=(2x-1) cm, panjang AC=.... CM A. 9 B.12 C.15 D.16 E.15

semoga saja bisa membantu

AG=akar[AB^2+BC^2+CG^2]=(2x-1)
<=> akar[x^2+(x+3)^2+(x-1)^2]=(2x-1)
<=> akar[x^2+x^2+6x+9+x^2-2x+1]=(2x-1)
<=> [3x^2+4x+10]=[2x-1]^2
<=> 3x^2 + 4x + 10 = 4x^2 - 4x + 1
<=> 4x^2 - 3x^2 - 4x - 4x + 1 - 10 = 0
<=> x^2 - 8x - 9 = 0
<=> (x - 9)(x + 1) = 0
<=> x - 9 = 0 atau x + 1 = 0
<=> x = 9 atau x = -1
x = 9 ...... x =/= -1 (x tidak sama dengan -1)
jadi panjang AC = akar [AB^2+BC^2]
= akar [x^2+(x+3)^2]
= akar [9^2+(9+3)^2]
= akar [9^2+12^2]
= akar [81+144]
= akar 225
= 15 cm (C)(E)