Question

1 tìm x biết

\(\dfrac{13}{4}\)+\(\dfrac{43}{5}\)x=\(\dfrac{9}{16}\)

\(\left[3x-5\right]=4\)

Answer 1

\(\dfrac{13}{4}\)+\(\dfrac{43}{5}\)x= \(\dfrac{9}{16}\)

\(\dfrac{43}{5}\)x =\(\dfrac{9}{16}\)-\(\dfrac{13}{4}\)

\(\dfrac{43}{5}\)x = \(\dfrac{-43}{16}\)

x = \(\dfrac{-43}{16}\):\(\dfrac{43}{5}\)

x= \(\dfrac{-43}{16}\).\(\dfrac{5}{43}\)

x= \(\dfrac{-215}{688}\)

vậy x = \(\dfrac{-215}{688}\)

b)|3x-5|=4

ta có 3x-5=4 hoặc 3x-5=-4

Th1 : 3x-5=4

3x=4+5

3x=9

x=\(\dfrac{9}{3}\)

x = 3

Th2 : 3x-5=-4

3x = -4+5

3x = 1

x = \(\dfrac{1}{3}\)

vậy x = 3

x = \(\dfrac{1}{3}\)