The price now is (80/100)x70 = (5600/100) = $56;

**Answer:**

infinite solutions

**Step-by-step explanation:**

The coefficient of x in the first equation is 3 times the coefficient of x in the second equation. This means we can **eliminate x **by **subtracting** 3 times the **second equation** **from the first**:

(15x +12y) -3(5x +4y) = (18) -3(6)

0 = 0 . . . . . simplify (true for all values of x or y)

**The system of equations has an infinite number of solutions**.

Let the number of 2 point shots Sarah made = X

Let the number of 3 point shots Sarah made = Y

Total number of shots Sarah made in all is 8 and it is already given in the problem.

Now in the question, it is also given that Sarah made three times as many 2 point shots as 3 point shots.

Then

X = 3Y

Now we can easily write the equation as

X + Y = 8

3Y + Y = 8

4Y = 8

Y = 8/4

Y = 2

Then the number of 2 point shots Sarah made = 2 * 3

= 6

So Sarah made a total of 6 two point shots.

So it is a straight line question

so we will use equation of straight line

**Answer:**

The speed in still water is 5 miles per hour.

**Step-by-step explanation:**

distance with current = 90 miles

distance against current = 10 miles

speed in still water = s

speed of current = 4 mph

speed with current = s + 4

speed against current = s - 4

time = t

speed = distance/time

distance = speed * time

With current:

90 = (s + 4) * t

Against the current:

10 = (s - 4) * t

We have a system of equations:

90 = (s + 4) * t

10 = (s - 4) * t

90 = ts + 4t

10 = ts - 4t

Subtract the second equation from the first equation.

80 = 8t

10 = t

t = 10

10 = t(s - 4)

10 = 10(s - 4)

1 = s - 4

s = 5

Answer: The speed in still water is 5 miles per hour.