Answer:
21.8° (22° to the nearest degree)
Step-by-step explanation:
Using cosine law:
a² = b² + c² - 2bc(cosA)
3² = 5² + 7² - 2(5)(7)cosA
cosA = 13/14
A = 21.7867893
Approximately angle: 22°
Hi there!
So, our two equations are:
2x + 3y = 20 and
-2x + y = 4
We can see that the x's will cancel out because they're the same number, opposite signs. Then we're left with 4y = 24.
Divide 24 by 4, which is 6.
y = 6, then we plug that in to the first equation for y:
2x + 3(6) = 20
2x + 18 = 20
2x = 2
x = 1
So, she made her first mistake when adding the equations, adding 20 and 4, she somehow got 16.
The solution to the system is (1,6).
I hope I helped!
Answer:
(1) N or n = 20
(2) = 43.4
(3) σ = 9.78 and s = 10.04.
Step-by-step explanation:
Answer:
-x^2+4x+6
Step-by-step explanation:
f(x) = 4x+1
g(x) = x^2 - 5
(f-g) (x) = 4x+1 - ( x^2 - 5)
Distribute the minus sign
= 4x+1 - x^2 +5
Combine like terms
= -x^2+4x+6
If she read 20 in half an hour how many can she read in 1 hour=40
so, that gets you 120 the answer is she can read 120 pages in 3 hours
