How do you solve and check your solutions to #-21=-3/5t#?

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Answer 1 · 2017-04-15T18:14:04

#t=35#

Our main goal here is to make #t# stand alone

We can start by writing what is on the left hand side as a fraction.

#(-21)/1=-3/5t#

Now let's cross product or cross multiply to get rid of the fractions

#-21xx5=1xx-3t#

Simplify

#-105=-3t#

Divide both sides by #-3#

#(cancel(-)105)/(cancel(-)3)=(cancel(-3)t)/(cancel(-3)#

#t=105/3=(cancel3xx35)/cancel3#

#rArrt=35#

To check, you simply substitute #t=35# into the original equation.

#-21=-3/5t, t=35#

#-21=-3/5xx35#

#-21=-105/5#

Cross product

#-21xx5=-105#

#-105=-105#

BAM!