Question 613692
{{{ 3x+2*(x+4)=5*(x+1)+3 }}}
{{{ 3x + 2x + 8 = 5x + 5 + 3 }}}
Get the x's all on one side, so subtract
{{{ 5x }}} from both sides
{{{ 3x + 2x - 5x + 8 = 5 + 3 }}}
Subtract {{{8}}} from both sides
{{{ 5x - 5x = 8 - 8 }}}
{{{ 0 = 0 }}}
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What's up? Why don't I get "x = something"?
That's because the equation is an "identity".
An identity just states that {{{ 4 = 4 }}}, or
something like it.
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To prove it's an identity, I should be able to plug in any value
for {{{ x }}}, and the equation will be true, so I'll say {{{ x = 13 }}}
{{{ 3x+2*(x+4)=5*(x+1)+3 }}}
{{{ 3*13+2*(13+4)=5*(13+1)+3 }}}
{{{ 39 + 2*17 = 5*14 + 3 }}}
{{{ 39 + 34 = 70 + 3 }}}
{{{ 73 = 73 }}}
yup, it's an identity