Find the range of function y = (2x & sup2; + 4x-7) / (X & sup2; + 2x + 3)

Y = (2x & # 178; + 4x + 6-13) / (X & # 178; + 2x + 3) = 2-13 / ((X & # 178; + 2x + 1) + 2); range [- 4.5,2)

Function y = 2x / X & # 178; - x + 1 (x)

Hope to adopt yo (computer photo is not very clear.)

Find the value of F (3) - f (- 2) + F (1) with piecewise function y = x & # 178;, X ≤ - 1 and X + 2, - 1 < x < 2 and 2x, X ≥ 2

f（1）=x+2=1+2=3
f（-2）=x^2=(-2)^2=4
f（3）=2X=2*3=6
f（3）-f（-2）+f（1)= 6-4+3=5

What are the meanings of "one positive, two definite, three-phase, etc." in the mean inequality

A + B = 2 * radical (AB) - positive: A, b 0: the product of a and B is a definite value
Three phase: that is to say, after using this inequality, we must verify whether "=" is true
The method is to see if a + B equals 2 * radical (AB) when a = B

The speed ratio of the two vehicles is 8:9. How many kilometers do the two vehicles travel per hour?

612 △ 4.5 = 136 (km), 8 + 9 = 17136 × 817 = 64 (km), 136 × 917 = 72 (km). A: car a travels 64 km per hour, car B 72 km per hour

If the solution set of inequality 1 / 2 (x-m) greater than 3-m is x greater than 1, then the value of M is?

1 / 2 (x-m) greater than 3-m
x-m>6-2m
x>6-m
x>1
6-m=1
m=5

The distance between a and B is 980km. A bus and a truck are running from two places at the same time. After 7 hours, they meet. The bus runs 60km per hour, and the truck runs 60km per hour

Truck speed = 980 △ 7-60 = 80 km / h

Given the function f (x) = CX / (2x + 3), where x ≠ - 3 / 2, if f [f (x)] = x, find the real number C

The undetermined coefficient method should be used
F [f (x)] = x, directly substituting f (x) = CX / (2x + 3) into X
The result is: (C ^ 2 * x) / [(2C + 6) x + 9x] = X
Finally, we get that: C ^ 2 * x = (2C + 6) x ^ 2 + 9x must be constant
Then C ^ 2 = 9 (the coefficients of primary and secondary terms should be the same)
2C + 6 = 0, and C = - 3

Team a and team B jointly built a road. Team a built 5 / 13 of the road. How much less did team a build than team B?
emergency

1-5/13-5/13=3/13

How many natural numbers less than 1000 can be composed of numbers 0, 1, 2, 3 and 4?

4*5*5+4*5+4=124
I do it according to 0, which is not a natural number

Find the range of function y = (2x & sup2; + 4x-7) / (X & sup2; + 2x + 3)