a/
$x+$$\frac{1}{4}$=$\frac{3}{4}$
$⇔x=$$\frac{3}{4}$-$\frac{1}{4}$
$⇔x=$$\frac{1}{2}$
$vậy$ $x=$$\frac{1}{2}$
b/$3/4-2/5x=29/60$
$⇔-2/5x=29/60-3/4$
$⇔-2/5x=29/60-45/60$
$⇔-2/5x=-4/15$
$⇔x=-4/15 : (-2/5)$
$⇔x=2/3$
$vậy$ $x=2/3$
c/
$2-x÷3/4=1/2$
$⇔x÷3/4=2-1/2$
$⇔x÷3/4=3/2$
$⇔x=3/2.3/4$
$⇔9/8$
$vậy$ $x=9/8$
d/
$\frac{37-x}{x+13}$ $=37$
$⇔37-x=37(x+13)$
$⇔37-x=37x+481$
$⇔x-37x=481-37$
$⇔-36x=444$
$⇔x=-37/3$
$Vậy$ $x=-37/3$