Question 168310
{{{x+(3/10)=-2/5}}}  multiply all terms by 10

{{{10x+3=-4}}} subtract 3 from both sides

{{{10x=-7}}}

{{{highlight(x=-7/10)}}}

so the answer is not -7 but -7/10

remember -2/5 is the same as -4/10

so -7/10+3/10=-4/10

hope that helps