The truck runs at a speed of 130 kilometers per hour, which is limited by 50 kilometers according to traffic regulations

Solution: (1) 130 km travel time: 130 / X
Fuel cost = gasoline price * time * fuel consumption per hour
Fuel charge = 2 * 130 / X * (2 + x ^ 2 / 360) = 520 / x + 13X / 18,
Total cost = fuel cost + driver's salary, y = 520 / x + 13X / 18 + 14 * 130 / x = 2340 / x + 13X / 18
(2) Find y derivative y '= - 2340 / x ^ 2 + 13 / 18, find out x = 56.92, y get the minimum value when x = 56.92, then y = 82.2

In order to simplify the following calculation, what number should I fill in? Fill in two and write the process
37.68-5.42-mouth 58.36 - (mouth + 3.28)
37.68-5.42-mouth 58.36 - (mouth + 3.28)

37.68—5.42—4.58
=37.68-(5.42+4.58)
=37.68-10
=27.68
58.36—（6.72+3.28）
=58.36-10
=48.36

A calculation problem (simplification)
(A & sup2; + 9) & sup2; - (a + 3) (3-A) (A & sup2; + 9) use the formula to simplify,

（a²+9）²-（a+3）（3-a）(a²+9）=（a²+9）²+（a+3)(a-3)(a²+9）=（a²+9)²+（a²-9)(a²+9）=（a²+9)(a²+9+a²-9)=（a²+9)2a²=2a^4+18a&s...

Calculation problem, simplification
12（x-0.5）
-5（1-1/5x)
-5a+(3a-2)-(3a-7)
1/3(9y-3)+2(y+1)
Preview, want to check
Can you give me a process

They're 12x-6
-5+x
-5a+5
5y+1

Simplify the calculation!
Root 12 + root 27 root 32 * root 72
——————- + -------------
Root number 3 root number 8

(root 12 + root 27) / (root 3) + (root 32 × root 72) / root 8
= (2 radical 3 + 3 radical 3) / radical 3 + (4 radical 2 × 6 radical 2) / 2 radical 2
= (2 + 3) + (24 × 2) / 2 radical 2
= 5 + 24 / radical 2
= 5 + 12 radical 2

1. The fourth power of X - the fourth power of Y 2x - Y (X & sup2; + Y & sup2;) & sup2;
—————————— ——————— /——————
2x²+xy-y² xy-y² y²
2.m-n mn+n² mn
——————-- - [subtraction before multiplication]
m²-2mn+n² m²-n² n-1
3.a+b a²-2ab b
——————/- + - [add first, then divide]
a a²-4b² a+2b

1.（ x²+y²）(x+y)(x-y) (2x-y) y.y y
________________ * ____________ *_____ Results________
(2x-y)(x+y) (x-y)y （ x²+y²）² (x²+y²)
2.(1-n) mn mn
_______ * _____ Results_____
(m-n) (n-1) n-m
3.(a+b) (a+2b) a+2b
_______ * _______ Results_______
a (a+b) a

Practical problems of fraction
A train departs from the station, with an estimated journey of 450 km. After it leaves for 3 hours, it stops one more station for special tasks, which delays 30 minutes. Later, it increases the speed by 20%. As a result, it arrives at the destination on time and asks for the original speed of the train

Set the original speed X
3+0.5+（450-3X）÷（X+20%X）=450÷X
3.5+（450-3X）÷1.2X=450÷X
Multiply both sides by 1.2x
4.2X+450-3X=540
1.2X=90
X=75

Mathematical calculation problem, simplification problem
(1) The fourth power of a ／ the fifth power of a × (- 3a) & # 178;
(2) A & # - 4 / 4 + 2-A 1 / 4 factorization

(1) The fourth power of a △ the fifth power of a × (- 3a) &# 178; = the fourth power of a × 9a &# 178; △ the fifth power of a = 9A. (2) (a &# 178; - 4) of 4 + (2-A) of 1 = [(a + 2) (A-2)] of 4 - (A-2) of 1 = [(a + 2) (A-2)] of (4-a-2) = [(a + 2) (A-2)] of (2-A) = (a + 2) of 1

There is a cylinder with a height of 13cm and a circumference of 10cm at the bottom. On the bottom of the cylinder, there is an ant at point a who wants to eat food at point B 1cm from the bottom. What is the shortest distance to crawl?

According to the meaning of the title, be = ef-fb = 13-1 = 12cm, because the perimeter of the bottom is 10cm, so the half perimeter of the bottom is 5cm, that is, AE = 5cm, be = 12cm, ab = 52 + 122 = 13cm

1 （√6-2√24）x√3-6√(1\8)
=3√2-12√2-6√(2√2\8)
At this point, how to simplify the following?
2 √(2\3)-4√54+42√(1\6)
=√6\3-12√6+42(√6\6)
At this point, how to simplify the following?
3 √(2\3)-4√216+42√(1\6)
=√6\3-24√6+42(√6\6)
At this point, how to simplify the following?

1. 6 √ (2 √ 2 / 8) this step is wrong! The original solution = (√ 6-2 √ 24) x √ 3-6 √ (1 / 8) = 3 √ 2-12 √ 2 - (3 √ 2) / 2 = - 9 / 2 (√ 2) 2, the original solution = √ (2 / 3) - 4 √ 54 + 42 √ (1 / 6) = √ 6 / 3-12 √ 6 + 7 √ 6 = - (14 √ 6) / 33, the original solution = √ (2 / 3) - 4 √ 216 + 42 √ (1 / 6) = √ 6 / 3-24 √ 6

The truck runs at a speed of 130 kilometers per hour, which is limited by 50 kilometers according to traffic regulations