Question 152268
# 1




{{{3x-7x=0}}} Start with the given equation.



{{{-4x=0}}} Combine like terms on the left side.



{{{x=(0)/(-4)}}} Divide both sides by {{{-4}}} to isolate {{{x}}}.



{{{x=0}}} Reduce.



----------------------------------------------------------------------


Answer:


So the answer is {{{x=0}}}



<hr>


# 2




{{{x^2+4=4x}}} Start with the given equation.



{{{x^2+4-4x=0}}} Subtract 4x from both sides.



{{{x^2-4x+4=0}}} Rearrange the terms.



Notice we have a quadratic equation in the form of {{{ax^2+bx+c}}} where {{{a=1}}}, {{{b=-4}}}, and {{{c=4}}}



Let's use the quadratic formula to solve for x



{{{x = (-b +- sqrt( b^2-4ac ))/(2a)}}} Start with the quadratic formula



{{{x = (-(-4) +- sqrt( (-4)^2-4(1)(4) ))/(2(1))}}} Plug in  {{{a=1}}}, {{{b=-4}}}, and {{{c=4}}}



{{{x = (4 +- sqrt( (-4)^2-4(1)(4) ))/(2(1))}}} Negate {{{-4}}} to get {{{4}}}. 



{{{x = (4 +- sqrt( 16-4(1)(4) ))/(2(1))}}} Square {{{-4}}} to get {{{16}}}. 



{{{x = (4 +- sqrt( 16-16 ))/(2(1))}}} Multiply {{{4(1)(4)}}} to get {{{16}}}



{{{x = (4 +- sqrt( 0 ))/(2(1))}}} Subtract {{{16}}} from {{{16}}} to get {{{0}}}



{{{x = (4 +- sqrt( 0 ))/(2)}}} Multiply {{{2}}} and {{{1}}} to get {{{2}}}. 



{{{x = (4 +- 0)/(2)}}} Take the square root of {{{0}}} to get {{{0}}}. 



{{{x = (4 + 0)/(2)}}} or {{{x = (4 - 0)/(2)}}} Break up the expression. 



{{{x = (4)/(2)}}} or {{{x =  (4)/(2)}}} Combine like terms. 



{{{x = 2}}} or {{{x = 2}}} Simplify. 



So the only answer is {{{x = 2}}}