Question

1

a) \(\left(x-1\right)^5=-243\)

b)\(\dfrac{x+2}{11}+\dfrac{2+x}{12}+\dfrac{x+2}{13}=\dfrac{+2x}{14}+\dfrac{x+2}{15}\)

c)x-2\(\sqrt{x}\)=0

Answer 1

a, \(\left(x-1\right)^5=-243\)

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

=> x-1= -3

=> x= -2

Answer 2

b, \(\dfrac{x+2}{11}+\dfrac{2+x}{12}+\dfrac{x+2}{13}=\dfrac{2+x}{14}+\dfrac{x+2}{15}\)

=> \(\dfrac{x+2}{11}+\dfrac{2+x}{12}+\dfrac{x+2}{13}-\dfrac{2+x}{14}+\dfrac{x+2}{15}=0\)

=>\(\dfrac{x+2+2+x+x+2-2+x+x+2}{11+12+13-14+15}\)

=> \(\dfrac{x+2}{37}=0\)

=> x+2= 0

=> x=-2