If #3(4-2x) = 0# and #2y+4=4#, then what is the value of #x^2+y^2#?

3 Answers
Aug 3, 2018

# x^2+y^2=4#

Explanation:

Here,

#3(4-2x)=0#

Dividing both sides by #3# ,we get

#4-2x=0#

#i.e. 2x-4=0#

Adding #4# both sides ,

#2x-4+4=0+4#

#:.2x=4#

Dividing both sides by #2# ,we get

#color(red)(x=2#

Again,

#2y+4=4#

Adding #(-4)# both sides

#2y+4+(-4)=4+(-4)#

#:.2y=0#

Dividing both sides by #2# ,we get

#color(red)(y=0#

So ,

#x^2+y^2=color(red)((2)^2+(0)^2#

#:. x^2+y^2=4#

Aug 3, 2018

The value of #x^2 + y^2# is #4#.

Explanation:

Simplify both equations and solve for #x# and #y#:

#3(4-2x) = 0#

Distribute the right hand side:
#12 - 6x = 0#

Subtract #color(blue)12# from both sides:
#12 - 6x quadcolor(blue)(-quad12) = 0 quadcolor(blue)(-quad12)#

#-6x = -12#

Divide both sides by #color(blue(-6)#:
#(-6x)/color(blue)(-6) = (-12)/color(blue)(-6)#

#color(red)(x = 2)#

#2y + 4 = 4#

Subtract #color(blue)4# from both sides:
#2y + 4 quadcolor(blue)(-quad4) = 4 quadcolor(blue)(-quad4)#

#2y = 0#

Divide both sides by #color(blue)2#:
#(2y)/color(blue)2 = 0/color(blue)2#

#color(red)(y = 0)#

We want the value of #x^2 + y^2#, so:
#2^2 + 0^2 = 4 + 0 = color(red)(4)#

Hope this helps!

Aug 4, 2018

#x^2+y^2=4#

Explanation:

We can solve for #x# and #y#, and then square them to find the value of #x^2+y^2#.

We have the following:

#3(4-2x)=0#

We can divide both sides by #3# to get

#-2x+4=0=>-2x=-4=>color(blue)(x=2)#

We also have

#2y+4=4#

We can subtract #4# from both sides to get

#2y=0=>color(red)(y=0)#

Now, let's plug these values into #x^2+y^2# to get

#color(blue)(2^2)+color(red)(0^2)=4+0=4#

Hope this helps!