How do you solve #15= - d + 20#?

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Answer 1 · 2016-09-24T00:18:30

#d = 5#

Subtract #20# from both sides. This gets us the equation

#15 - 20 = - d + 20 - 20#

#-5=-d#

You then can multiply both sides by #-1# to get

#-5 * (-1) = -d * (-1)#

#5=d#

The other way to do this is to add #d# to both sides to get

#15+d=20#

and then subtract #15# from both sides to get

#5=d#

Either way, both of these work.