Answer:
(1.13, 7.74) and (-4.13, 18.26)
Step-by-step explanation:
This can be solved in two ways: mathematically and graphically.
<u>Graphing</u>
Plot both lines and find where they intersect. See the attachment.
The intersection points are (1.13, 7.74) and (-4.13, 18.26)
<u>Mathematical</u>
y + 2x = 10
y = 10 - 2x
y = 3x² + 7x - 4
10 - 2x = 3x² + 7x - 4
3x² + 9x - 14 = 0
Solve this using the quadratic equation:
x = 1.13 and -4.13
Use these two values of x to find y:
y = 10 - 2x
y = 10 - 2(1.13)
y = 7.74
y = 10 -2x
y = 10 -2(-4.13)
y = 18.26
The two points are:
(1.13, 7.74) and (-4.13, 18.26)
Answer:
Step-by-step explanation:
Answer:
x = 21
Step-by-step explanation:
The sum the the interior angles of a triangle is 180°.
We know that the three angles of the triangle is 100°, x° - 4, and 3x°.
The sum of 100°, x° - 4, and 3x° must equal 180°. We can turn this into the equation:
100 + x - 4 + 3x = 180
(I got rid of the degree signs because they are not necessary when finding x.)
Now, to find the value of x, we would have to solve for x in the equation 100 + x - 4 + 3x = 180.
100 + x - 4 + 3x = 180
Subtract 100 from both sides to get rid of the 100 on the left side.
x - 4 + 3x = 180 - 100
Simplify.
x - 4 + 3x = 80
Add 4 from both sides to get rid of the -4 on the left side.
x + 3x = 80 + 4
Simplify and combine like terms.
4x = 84
Divide 4 from both sides to get rid of the coefficient of 4 on the left side.
x = 84/4
Simply.
x = 21
The value of x would be 21.
x = 21
I hope you find this helpful. :)
Answer: 13
Althoug each round trip takes 9 minutes and can carry 5 people on the boat, you can not just divide the 20 minutes time by 9 and multiply by 5 to find the number of people that are saved without getting wet.
First trip:
5 people take the boat to the island but only 4 can stay, because one has to return with the boat to the ship to rescue other 4 people.
So, when 9 minutes have passed, 4 people are safe on the island and the boat is again by the ship.
Second trip:
In the second trip, other 4 people are rescued,along with "sailor" who returned in the boat to rescue them.
When it has passed 18 minutes, the boat is next to the ship agin to carry other 4 people before the boat sinks.
This is the last trip before the boat sinks. So, the total number of passengers rescued is 4 + 4 + 5 = 13
