Answer:
a=-4, b=-4. (-4, -4).
Step-by-step explanation:
-3a+7b=-16
-9a+5b=16
-------------------
-3(-3a+7b)=-3(-16)
-9a+5b=16
---------------------------
9a-21b=48
-9a+5b=16
------------------
-16b=64
b=64/-16
b=-4
-3a+7(-4)=-16
-3a-28=-16
-3a=-16+28
-3a=12
a=12/-3
a=-4
Answer:

Step-by-step explanation:
The equation of a circle is given by
, where
is the center of the circle and
is the radius of the circle.
From the diagram, we can find the following:
- the radius of the circle is 4
- the center of the circle is located at (1,6)
Thus, we have:

Answer:
Step-by-step explanation:

Speed of the boat = u
speed of the current = v
In downstream,
u - v = 280/7
u - v = 40
In upstream,
u + v = 280/14
u + v = 20
Add both equations
2u = 60
u = 30
v = -10
Speed of the boat = 30 km/h
Answer:
do you have a picture of the graph?