Question #2236d
2 Answers
There are a few different ways to approach it, but I've shown one below.
In this case the solution is
Explanation:
Equations can be solved in different ways, as long as whatever we do to one side we do to the other. Here's one way to solve this one:
Divide both sides by 2:
Expand and simplify the brackets:
Subtract 8 from both sides:
This is a standard form for quadratic equations,
That means
Explanation:
#"isolate "(x+3)^2" by dividing both sides of the equation by 2"#
#cancel(2)/cancel(2)(x+3)^2=16/2#
#rArr(x+3)^2=8#
#color(blue)"take the square root of both sides"#
#sqrt((x+3)^2)=+-sqrt8larrcolor(blue)" note plus or minus"#
#rArrx+3=+-sqrt8=+-sqrt4xxsqrt2=+-2sqrt2#
#"subtract 3 from both sides"#
#xcancel(+3)cancel(-3)=-3+-2sqrt2#
#rArrx=-3-2sqrt2" or "x=-3+2sqrt2#
#rArrx~~ -5.828" or "x~~ -0.172" to 3 dec. places"#