So i've completely forgot how to do fractions from last semester :(. -2/5y= 1/7 solve for y. Do i find the lcd again or?

Question

anonymous · Answer

forgotten*

whpalmer4 · Answer

$$\frac{-2y}{5}=\frac{1}{7}$$I would multiply by 35 (5*7) and solve.  With only 1 term on each side, you could also do this by cross-multiplication:
$$\frac{a}{b}=\frac{c}{d}$$$$ad=bc$$

whpalmer4 · Answer

$$-2y*7=1*5$$$$-14y=5$$

whpalmer4 · Answer

Sometimes that's easier than finding the common denominator if you have some hairy expressions in the fractions

anonymous · Answer

whpalmer is right.

You can think of the fraction on the right becoming a "1", therefore the y is being isolated by itself. This is done by taking it's reciprocal. - 2/5 times -5/2 is one. Right? Whatever you do on one side an equal side you must do it on the other.

anonymous · Answer

Excuse me, you can think of the fraction on the left* 

:)