(5x - 2) . (3x + 1) + (7 - 15x) . (x + 3) = 20
=> 15x2 + 5x - 6x - 2 + 7x + 21 - 15x2 - 45x = 20
=> (15x2 - 15x2) + (5x - 6x + 7x - 45x) = 20 + 2 - 21
=> 0 + [x . (5 - 6 + 7 - 45)] = 1
=> -39x = 1
=> x = 1 : (-39)
Vậy x = \(\frac{-1}{39}\)
giup to 3 bai nay
1. gia tri x lon nhat thoa man : x2(5x-20)=15x
2 gia tri x >0 de -3x4+12x2+1 dat gia tri lon nhat
3. tap hop cac gia tri cua x thoa man : x4+x3+2x-4=0
1. gia tri x >1 thoa man (9x-7)2=(5-2x)2
2.tong binh phuong tat ca cac gia tri x thoa man : 2(x+5)=x2+5x
3. gia tri cua x3+y3 biet x+y=2 va x2+y2=20
giup to 2 bai nay
1. gia tri x lon nhat thoa man x2(5x-2)+6=15x
2. gia tri x>0 de -3x4+12x2+1 dat gia tri lon nhat
giup to 2 bai nay
1. gia tri x lon nhat thoa man x2(5x-2)+6=15x
2. gia tri x>0 de -3x4+12x2+1 dat gia tri lon nhat
giup to 2 bai nay
1. gia tri x lon nhat thoa man x2(5x-2)+6=15x
2. gia tri x>0 de -3x4+12x2+1 dat gia tri lon nhat
gia tri cua x thoa man
(4x-3).(5x+2)+(10x+7).(1-2x)=12
gia tri cua x > 0 thoa man 3x^2 + 2y^2 = 308 va 5x = 3y
1.tong binh phuong tat ca cac gia tri x thoa man : 2(x+5)=x2+5x
2. gia tri cua x3+y3 biet x+y=2 va x2+y2=20
1.gia tri a de da thuc P(x)=3x3-8x2+6x-a chia het cho Q(x)=3x2-5x+1 la a =?
2.khi a+b=1 .gia tri nho nhat cua bieu thuc a3+b3+ab la?
3.tong cac gia tri cua x thoa man x5=x4+x3+x2+x+2 la?
