In △ ABC, if AB = 15, AC = 13 and high ad = 12, the perimeter of △ ABC is () A. 42 B, 32 c, 42 or 32 D, 37 or 33

In △ ABC, if AB = 15, AC = 13 and high ad = 12, the perimeter of △ ABC is () A. 42 B, 32 c, 42 or 32 D, 37 or 33

C

The number of edges of a straight prism is a, the number of vertices is B, and the number of sides is C. If a + B + C = 30, the straight prism is straight_____ A prism

Analysis:
A = 4C-C = 3C (each face has four edges, minus the overlapping edges between each two faces)
B = 4C / 2 = 2C
∴6c=30
c=5
So it's a straight five prism

Please answer the math problem of grade 5 in detail, thank you! (15 16:19:38)
Forge a square steel block with the edge length of 4 decimeters into a cuboid with the length of 6 decimeters and the width of 3 decimeters. What is the height of the cuboid?

The volume of cube is 64
Cuboid volume is length by width by height
The volume of forging a cube into a cuboid is invariable
So divide length by width by volume

It is known that a and B are non-zero natural numbers, and a + B = 90. The maximum possible product of a and B is ()

√ ab ≤ (a + b) / 2 = 45, when a = B, take the equal sign, when a = B, AB is the largest, 45 ^ 2 = 2025

The sum of a natural number and its reciprocal is 101 / 10. The natural number is () 1.52.103.11

The sum of a natural number and its reciprocal is 101 / 10. The natural number is (2.10)

13 24 36 43 54 45 47 18 30 what should be the first and last number?

It's 713 24 36 43 54 45 47 18 30 37

Use the nine numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 to form prime numbers. If each number has to be used and can only be used once, how many prime numbers can these nine numbers form at most?

Can be composed of the following prime numbers: 2, 5, 7, 61, 43, 89, a total of 6. A: then these 9 numbers can be composed of up to 6 prime numbers

The image of the exponential function y = f (x) intersects with the counterpoint g (x) at the point (2,1 / 4). Find the analytic expression of the functions f (x) and G (x)
The image of exponential function y = f (x) and pair function y = g (x) intersects at point (2,1 / 4). Find the analytic expressions of functions f (x) and G (x)

Undetermined coefficient method: let the exponential function be y = a ^ x, and substitute the point (2,1 / 4) to get a = 1 / 2, so the exponential function is y = (1 / 2) ^ X
y=loga(x)
Then 1 / 4 = loga (2)
a^(1/4)=2
The solution is a = 16
So: y = log16 (x)

2.10,1 ,9,6,8,11,7,___ ,...What comes next?

10,1 ,9,6,8,11,7,16
law:
10,9,8,7
1+5=6,6+5=11,11+5=16

Factorization of x ^ 2-xy + 2yz-4z ^ 2

Primitive = (X & sup2; - 4Z & sup2;) - (xy-2yz) = (x + 2Z) (x-2z) - Y (x-2z) = (x-2z) (x + 2z-y)