Answer:
x = − 6 ± √ 51
Step-by-step explanation:
The quadratic formula is x= -b ± √b^2-4ac / 2a. A is 1, b is 12, and c would be -15 if we subtract the 15 to the other side. Plugging the numbers in would be x= -12 ± √12^2-4(1)(-15) / 2(1) . x= -12± √144+60/ 2 --> x=-12± √204/2 ---> x= -6± √51
X=1, -13
The original price was $500
20% of 500 is 100
3/8
13/16 - 7/16
= ( 13 - 7 )/16
= 6/16
= 3/8
$5.33
12 divided by 9=1.333333
6 divided by 4.5= 1.333333
4 multiplied by 1.333333=5.33