2x^2+20x=-38 divide both sides by 2
x^2+10x=-19, halve the linear coefficient, square it, than add that value to both sides of the equation, in this case add (10/2)^2=25...
x^2+10x+25=6 now the left side is a perfect square
(x+5)^2=6 take the square root of both sides
x+5=±√6 subtract 5 from both sides
x=-5±√6 (so answer c.)
5 hours and 20 minutes because 1/3 as a decimal is 0.3 continued (i wrote down 0.33 so its simplified) and 0.33 decimal hours is 20 minutes.
to inverse a equation make all y's x and andy x's y
Thus the inverse is
x=4y-8
Evaluated to
4y=x+8
y= \frac{1}{4}x +2
Since there is nothing attached for me to help you I looked for a website that can find the answer with an explanation. It is called quickmath it’s like a math calculator . Hopefully that helps you .