Question

xin moi nguoi hay giup not cau nay , day la bai cuoi roi ah!!

tim x:

e,(3x-1)(2x+7)-(x+1)(6x-5)=16

f,x(x+1)(x+6)-x^3=5x

Thanks moi nguoi trc va vo cung cam on ah!!~

Answer 1

e)(3x-1)(2x+7)-(x+1)(6x-5)=16

=>\(6x^2-2x+21x-7-6x^2-6x+5x+5\)=16

=>18x-2=16

=> 18x=18

=> x=1

Answer 2

b)\(x\left(x+1\right)\left(x+6\right)-x^3=5x\)

=>\(x\left(x+1\right)\left(x+6\right)-x^3-5x=0\)

=> \(x\left(x^2+x+6x+6\right)-x\left(x^2-5\right)=0\)

=>\(x\left[\left(x^2+7x+6\right)-\left(x^2-5\right)\right]=0\)

=> __x=1

     |__7x+1=0=> 7x=-1=> x=-1/7