x+(300-2x)+(170-x)+(150-x)=500
Need help with this problem. I know the solution is 200 but do not know how to achieve it.
you must use the distributive law outside the brackets. when there is no number present in front of the bracket, you must add an imaginary 1.
$\displaystyle x+(300-x)+(170-x)+(150-x)=500$
$\displaystyle
x+1(300-x)+1(170-x)+1(150-x)=500$
$\displaystyle x+300-x+170-x+150-x=500$
$\displaystyle x-x-x-x=500-300-170-150$
$\displaystyle -2x=-120$
$\displaystyle
x=60$