Question 286127
3 times a certain number plus 7 = 30


Just break it down to what they give you:


3 times:  This is like saying:  {{{3 * _?__}}}
a certain number: This is a number we don't know so we'll call it "x"
 plus 7:  This is {{{ (____+ 7)}}}
 = 30


Put it all together:  3x + 7 = 30


Now solve for x like this:


{{{3x + 7 = 30}}}
{{{3x = 30 - 7}}} (subtract 7 from both sides to isolate the "X")
{{{3x = 23}}} ({{{30 - 7 = 23}}})
{{{x = 23/3}}}  (divide both sides by 3 to isolate the  "x" further)


Plug in our "x" info and see if the statement is correct:


{{{3x + 7 = 30}}} original equation
{{{(3)(23/3) + 7 = 30}}} Plug {{{23/3}}} into the "x" variable of this equation.
{{{23 + 7 = 30}}}  
{{{30 = 30}}}  Yayyyy it works. :-)


I hope this helps you. :-)