Answer:
-8 + 3.2z
Step-by-step explanation:
- when there is a "+" in front of an expression in parentheses, the expression remains the same
- -2 + 6.45z - 6 - 3.25z
- calculate the difference
-8 + 6.45z - 3.25z
collect like terms
-8 + 3.2z
Answer:

Step-by-step explanation:
The equation of a line is usually written in the form of y=mx+c, where m is the gradient and c is the y-intercept.
Parallel lines have the same gradient. Hence the gradient of line r is
.
Susbt. m=
,

To find c, substitute a coordinate.
When x=3, y= -9,

-9= 1 +c
c= -9-1
c= -10
Thus the equation of line r is
.
Answer:
3 seconds
Step-by-step explanation:
When the ball hits the ground, the height will be 0. Therefore, you can substitute 0 in for the value of f(t), hence the equation will be:
0 = -16t^2 + 32t + 48
You can then factor out -16:
0 = t^2 - 2t - 3
Factor:
0 = (t-3)(t+1)
t = 3, -1
However -1 is an extraneous solution because time cannot be negative. Therefore, the answer is 3 seconds.