Answer:
C. -7x^2 - 28
Step-by-step explanation:
Firstly simplify the bracket before doing anything;
4x(3x - 7) = 12x^2 - 28x
then go back to the question and substitute the expression(12x^2 - 28x) on the bracket and then work out the question;
12x^2 - 28x -19x^2...then group the values with the same exponent of x,
(12x^2 - 19x^2) - 28x
; -7x^2 - 28x
So what you do is (2/3)x-9=7. Add 9 to both sides (2/3)x=16. Multiply by reciprocal on both sides 16 x (3/2). 16 x 3 = 48. 48/2=24
Speed = Distance / Time
Distance = Speed*Time
For this problem, we should bear in mind that current speed has an impact on the boat speed...
for upstream, the boat goes against the current, and so its speed is
U = V - C
where V is the speed of the boat
C is the current speed
for downstream, it will be:
D = V + C
Convert the problem into mathematical equations:
4D + 3U = 116
3D + 4U = 108
4(V+C) + 3(V-C) = 116
4V + 4C + 3V -3C =116
7V + C = 116
3(V+C) + 4(V-C) = 108
3V + 3C + 4V - 4C = 108
7V - C = 108
Solving the equations:
7V + C = 116
7V - C = 108
14V = 224
V = 16km/hr —-> speed of boat
to get C:
7(16) + C = 116
C = 4km/hr
I would either graph these (which would be a easiest) then you would see a line that goes through (0, -2) on the y-axis
And you can either determine the slope from the graph or pick two points above and find the slope.
or spread them out evenly and fill out the missing pieces.
-8. -4
-4. -3
0
4. -1
6. -0.5
8
12. 1
Fill in the middle values and you can put (6,-0.5) on there
What pattern do u see? This way would be pretty hard.
Equation: y=(1/4)x-2
4 2/3 divided by 2 3/6 divided with a calculator as a decimal would be 1.86666666667
