How to solve proportion?

-b/2 = -6/4

2 Answers
Apr 5, 2018

#b=3#

Explanation:

#(-b)/2 = (-6)/4#
By cross-multiplication:
#-4b = -12#
#b = -12/-4#
#b = 3#

Apr 5, 2018

See below.

Explanation:

To solve a proportion, we use the process known as "cross-multiplication ".

This process looks something like this:

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We are given the proportion:

#color(blue)(-b)/color(red)(2)=color(green)(-6)/color(purple)(4)#

Using the process of cross-multiplication, we should have:

#color(blue)(-b)/color(red)(2)=color(green)(-6)/color(purple)(4)#

#=> color(purple)(4)(color(blue)(-b))=color(red)(2)(color(green)(-6))#

#=> -4b=-12#

From here, we only need to solve for #b#:

#-4b=-12#

#=> (-4b)/color(red)(-4)=-12/color(red)(-4)#

#=> b=3#