i belive you add 17 on both sidees to find x
Answer:
Step-by-step explanation:
h is the height of the pebble after a certain amount of time has gone by. Since we are told to find that time when the pebble is on the ground, we say that h = 0 since the height of something on the ground has no height at all. Then factor the quadratic.

Throw that into the quadratic formula or however you were taught to factor irrational quadratics (maybe completing the square?) to get that
t = 11.27869 sec and t = -10.52869 sec
Since we all know that time will never carry a negative value, we will disregard it and go with 11.27869 seconds. Not sure to where you are told to round.
Answer:
No, because the number of trials is not fixed.
Step-by-step explanation:
a. pe. x
Answer:
7x+9y=45
Step-by-step explanation:
Standard equations always mean that you have to get x and y on one side so that they equal the coefficient.
Do this by adding the fraction that is combined with x to the other side where y is. The equation should now read 
Standard form cannot have fractions, so now you must multiply by the denominator (9) on both sides of the equation in order to cancel it out. Don't forget to multiply EACH variable by 9. This leads you to the answer.
Area of paralellogram=legnth times height
l=legnth
h=height
area=96
lh=96
h is 4 less than l
h=-4+l
sub
l(-4+l)=96
-4l+l^2=96
minus 96 both sides
l^2-4l-96=0
factor
(l-12)(x+8)=0
set to zero
l-12=0
l=12
l+8=0
l=-8, imossible, legnth cannot be negative, disreagard this soultion
legnth=12cm