5(x + 30)
x + 30 represents the number of minutes per day he practices
5 is the number of days he practices
so 5(x+30) = the total number of minutes he practices in 5 days
For example, if he practices the piano for 20 minutes per day and the violin for 30 minutes per day, he practices a total of 50 minutes per day. For 5 days that would be 5 x 50 = 250 minutes in 5 days.
Plug that into the equation
5(x+30) = 5(20+30) = 5(50) = 250
Answer:
10
Step-by-step explanation:
If the sides of the rectangle is 6cm and 8cm, then we mean that, the length and breadth are 6cm and 8cm
The diagonal which cross at AX will be the hypotenus of the triangle formed by drawing the diagonal.
Hence,
Hypotenus = sqrt (opposite² + adjacent²)
AX = sqrt[(8²) + (6²)]
AX = sqrt(64 + 36)
AX = sqrt(100)
AX = 10
Your answer is (a) because 4 times 2 is 8 but since it's negative 2 it's negative 8
Answer:
45.40
Step-by-step explanation:
First of all, the shape of rope is not a parabola but a catenary, and all catenaries are similar, defined by:
y=acoshxa
You just have to figure out where the origin is (see picture). The hight of the lowest point on the rope is 20 and the pole is 50 meters high. So the end point must be a+(50−20) above the x-axis. In other words (d/2,a+30) must be a point on the catenary:
a+30=acoshd2a(1)
The lenght of the catenary is given by the following formula (which can be proved easily):
s=asinhx2a−asinhx1a
where x1,x2 are x-cooridanates of ending points. In our case:
80=2asinhd2a
40=asinhd2a(2)
You have to solve the system of two equations, (1) and (2), with two unknowns (a,d). It's fairly straightforward.
Square (1) and (2) and subtract. You will get:
(a+30)2−402=a2
Calculate a from this equation, replace that value into (1) or (2) to evaluate d.
My calculation:
a=353≈11.67
d=703arccosh257≈45.40
