Question #35fdb

2 Answers
Dec 4, 2017

See a solution process below:

Explanation:

If the problem is to solve: #4/7x = 1/3#

Then multiply each side of the equation by #color(red)(7)/color(blue)(4)# to solve for #x# while keeping the equation balanced:

#color(red)(7)/color(blue)(4) xx 4/7x = color(red)(7)/color(blue)(4) xx 1/3#

#cancel(color(red)(7))/cancel(color(blue)(4)) xx color(blue)(cancel(color(black)(4)))/color(red)(cancel(color(black)(7)))x = (color(red)(7) xx 1)/(color(blue)(4) xx 3)#

#x = 7/12#

If the problem is to solve: #4/(7x) = 1/3#

Then multiply each side of the equation by #color(red)(3)color(blue)(x)# to solve for #x# while keeping the equation balanced:

#color(red)(3)color(blue)(x) xx 4/(7x) = color(red)(3)color(blue)(x) xx 1/3#

#color(red)(3)cancel(color(blue)(x)) xx 4/(7color(blue)(cancel(color(black)(x)))) = cancel(color(red)(3))color(blue)(x) xx 1/color(red)(cancel(color(black)(3)))#

#(color(red)(3) xx 4)/7 = color(blue)(x) xx 1#

#12/7 = x#

#x = 12/7#

Dec 4, 2017

You can solve it with cross multiplication!

Explanation:

We begin with your given equation: #4/7x=1/3#

On the left side of your equation, you can multiply #x# by #4/7# to get #(4x)/7#.

Next, we cross multiply both sides of your equation.

#(4x)/7=1/3#
#(4x)(3)=(7)(1)#

It's simple algebra from there!

#12x=7#
#x=7/12#