Question

Answer 1

a: \(3x\left(x-4\right)-x\left(5+3x\right)=-34\)

=>\(3x^2-12x-5x-3x^2=-34\)

=>-17x=-34

=>x=2

b: \(\left(3x+1\right)^2+\left(5x-2\right)^2=34\left(x+2\right)\left(x-2\right)\)

=>\(9x^2+6x+1+25x^2-20x+4=34\left(x^2-4\right)\)

=>\(34x^2-14x+5=34x^2-136\)

=>-14x=-141

=>\(x=\frac{141}{14}\)

c: \(x^3+3x^2+3x+1=0\)

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

=>x+1=0

=>x=-1

d: \(\left(x+3\right)^2-\left(2x-4\right)^2=3x\left(-x+2\right)\)

=>\(x^2+6x+9-\left(4x^2-16x+16\right)=-3x^2+6x\)

=>\(x^2+6x+9-4x^2+16x-16+3x^2-6x=0\)

=>16x-7=0

=>16x=7

=>\(x=\frac{7}{16}\)

e: \(8x^3-12x^2+6x-1=0\)

=>\(\left(2x-1\right)^3=0\)

=>2x-1=0

=>2x=1

=>x=1/2