Mathematics for junior high school knows that a is a real number, and finds the value of a 2 under t

This question needs to be discussed in a categorical manner.

When a+2<0, a-1 must be less than 0

Then the original formula = (-a-2)-(1-a)=-a-2-1+a=-3, when a+2>0, a-1>0.

Original formula = (a+2)-(a-1)=a+2-a+1=3, when a+2>0, a-1<0.

The original formula = (a+2)-(1-a)=a+2+a-1=2a+1 is used.

A (a<0) = -a under the root number

A (a<0) = -a under the root number

Hungry, I didn't expect to work so hard to type so many words, and someone snatched the sofa Woo woo woo.

1.A<-2, under the root number (a+2) 2-under the root number (a-1) 2=(-a-2)-(1-a)=-a-2-1+a=-3

2.-2 a<1, under the root number (a+2) 2-under the root number (a-1) 2=(a+2)-(1-a)=a+2-1+a=2a+1

3.A 1, under the root number (a+2) 2 - under the root number (a-1) 2=(a+2)-(a-1)=a+2-a+1=3

Hope it helps you o(o

1. When a 1, the original formula = a+2-(a-1)=3

2. When 1 a -2, the original formula = a+2 - (1-a) = 2a+1

3. When a -2, the original formula = -(a + 2) -(1-a) = -3

0 or more under the root number

So -a 2> = 0a 2

For the root number (-a 2) to be meaningful, then a=0

The loss is based on the original formula to check the empty rent = root number (a + 2) - root number (8-4a) + root number (-a 2) = root number 2 - root number 8 = negative root number defeat 2

Because the root number must be searched in the shed in the calendar is equal to 0, ie.

a-2≥0a≥2

So. The original form becomes Bubu.

a-1 root number a-2=a

Root number a-2=1

a-2=1a=3

Under the root number (a) Under the root number (a-1).

The numerator and denominator are also multiplied by [under the root number (a) under the root number (a-1)].

Under the root number (a) Under the root number (a-1) = 1 (under the root number (a) under the root number (a-1)).

In the same way: under the root number (a-2) - under the root number (a-3) = 1 (under the root number (a-2) + under the root number (a-3)).

Because a>=3

Under the root number (a) Under the root number (A-1)) > under the root number (A-2) + under the root number (A-3)) >0

1 (under (a) (a-1)) < 1 ((a-2) + (a-3)).

So: under the root number (a) under the root number (a-1) under the root number (a-2) - under the root number (a-3).

Root number (1-a) Root number a-2 a

If a-2 is greater than or equal to 0, we can find greater than or equal to 2

Therefore, the root number (1-a) The root number a-2 a is simplified to (a-1) + the root number a-2 a to obtain a=3

The root number-a makes sense.

a²>=0

a=0 substitute a=0 into the root number a+2-root number 2-a + root number-a to get the original formula = 2- 2+0=0

Knowing that a is a real number, find the root number (a+16)-root number (9-a) + root number (-a 2) solution: (a+16)- 9-a) + a ) the number in the root number 0, -a 2=0, a=0 substituting the formula to obtain.