Answer:
I am guessing , atleast 8
Step-by-step explanation:
If we multiply the bottom equation by 2 and move x to the right, it becomes:
4y = 2x-38
Now we can substitute it for the 4y in the top equation:
3x + (2x-38) = -23 => 5x = -23+38 => 5x = 15 => x=3
Then 4y = 2*3-38 => y = -8
So the solution is (3,-8)
<span><span> <span>Akar akar persamaan kuadrat 2x² - 3x -1 = 0 adalah x1 dan x2. Persamaan kuadrat baru yang akar akarnya satu lebih kecil dari dua kali akar akar persamaan kuadrat di atas adalah ........</span></span><span><span><span>A.x² - x - 4 = 0</span><span>B.x² + 5x - 4 = 0</span><span>C.x² - x + 4 = 0</span></span><span><span>D.x² + x + 4 = 0</span><span>E.x² - 5x - 4 = 0</span></span></span><span>Jawaban : A
Penyelesaian :
Akar-akar persamaan lama : x1 dan x2
Akar-akar persamaan baru : xA dan xB
xA = 2x1 - 1
xB = 2x2 - 1
xA + xB = (2x1 - 1) + (2x2 - 1)
= 2 (x1 + x2) - 2
= 2 () - 2
= 3 - 2
xA + xB = 1
xA . xB = (2x1 - 1) (2x2 - 1)
= 4 x1.x2 - 2(x1 + x2) + 1
= 4.(-) - 2() + 1
= -2 - 3 + 1
xA . xB = -4
Jadi persamaan kuadrat baru : x² - (xA + xB)x + xA . xB = 0
x² - x - 4 = 0
</span></span>
Answer:
It should be 1,628
.
Step-by-step explanation:
We see two shapes in the figure and those shapes are a rectangle and a circle. Let's find the area of the circle first. 25m won't help us find the area of the circle so let's pretend that 25m isn't there for now. 40m seems to be the diameter of the circle and to find the area of the circle we need to multiply the radius squared by Pi or 3.14. Half of 40 is 20 so we can multiply 20 squared by Pi to give us 1,256.63706. Do not round this number yet. As you can see this circle isn't a full circle. It's a semicircle. We can divide 1,256.63706 by 2 to find the area of a semicircle. You should get 628.31853 and round that to the nearest tenth and we get 628.32. Now let's keep that number in mind and find the area of the rectangle. Using a calculator we can easily multiply 40 and 25 to find the area of the rectangle, which is 1,000. Add 1,000 and 628.32 and our final results should be 1,628.32. I don't see this number in your options but option B is closely related to this answer. I hope this helps and if this answer is wrong then please give me some feedback on what I did wrong! Thank you!