Let 11x + 15y + 23 = 0 be equation (1)
And 7x - 2y - 20 = 0 be equation (2)
Multiply equation (1) by 2:
22x + 30y + 46 = 0
Multiply equation (2) by 15:
105x - 30y - 300 = 0
Add equations (1) and (2):
22x + 105x + 30y - 30y + 46 - 300 = 0
127x - 254 = 0
127x = 254
x = 254/127
[x = 2]
Substitute x = 2 in equation (1) to find y:
11(2) + 15y + 23 = 0
22 + 15y + 23 = 0
15y + 45 = 0
15y = -45
y = -45/15
y = -3
Therefore, x = 2 and y = -3.
Answer:
The speed with which Ryan was rowing was 4 mph
Step-by-step explanation:
With a small boat, Ryan wants to row towards an island and come back at a speed of x mph and the island is 20 miles away from him.
Therefore, total 20 + 20 = 40 miles he rowed for 5 hours.
On the way to the island, there was a wind of 4 mph in the direction of his motion and on the way back also there was a wind of 4 mph in the direction of his motion.
So, in the total journey, he has a speed of (x + 4) mph.
Therefore,
⇒ x + 4 = 8
⇒ x = 4 mph.
Therefore, the speed with which Ryan was rowing was 4 mph. (Answer)