It might be 31 if you add all the numbers together but I'm not positive.
Answer:
I think it would all of them, I could be wrong though
Step-by-step explanation:
To find if one of these is a correct triangle you would need the sum of 2 sides to be longer than the third
A: ⇒ 4 + 9 > 7
B: ⇒ 5 + 12 > 13
C: ⇒ 20 + 22 > 24
therefore making A, B, and C the answer.
let me know if I'm wrong >:3
x= 3+√5/4,3-√5/4
Step-by-step explanation:
1.In general, given ax^2+bx+c=0, there exists two solutions where:
x= -b+√b^2 - 4ac/2a, -b-√b^2-4ac/2a
2.In this case, a=4, b=-6 and c=1.
x=6+√(-6)^2-4×4/2×4, 6-√(-6)^2-4×4/2×4
3.Simplify.
x=6+2√5/8, 6-√5/8
4.Simplify solutions.
x=3+√5/4, 3-√5/4
Let x and y represent the hourly rates of the first and second mechanics, respectively.
.. x + y = 205 . . . . . . . the sum of the two rates was $205 per hour
.. 5x +15y = 1925 . . . . they charged a total of $1925
Divide the second equation by 5, then subtract the first equation.
.. x +3y = 385
.. (x +3y) -(x +y) = (385) -(205)
.. 2y = 180
.. y = 90
.. x = 205 -y = 115
The first mechanic charged $115 per hour; the second charged $90 per hour.
