1.tìm x \(\in\) Q biết:
a)\(\left(-\dfrac{1^3}{3}\right)\cdot x=\dfrac{1}{81}\)
b)\(\left(x\cdot5\right)^3=-64\)
c)\(\left(2x-3\right)^2-9=0\)
d)\(\left(5x+1\right)^2=\dfrac{36}{49}\)
2.tìm x,y biết:
a)\(x^2+\left(y-\dfrac{1}{10}\right)^4=0\)
b)\(\left(\dfrac{1}{2}x-5\right)^{20}+\left(y^2-\dfrac{1}{4}\right)^{40}\le0\)
giúp mình nhé các bn thân yêu !thank