Question

A-(4a-11)+(9-2а)=20-5а доказать тождетство

Answer 1

a-4a+11+9-2a= 20-5a. левая часть равна правой , тождество доказано. 11+9=20, (a-4a-2a= -5a).

Answer 2

To prove the identity A-(4a-11)+(9-2a) = 20-5a, we need to demonstrate that the left-hand side (LHS) of the equation simplifies to the same expression as the right-hand side (RHS) for all valid values of 'a'.

Let's begin:

LHS: A - (4a - 11) + (9 - 2a)

Step 1: Distribute the negative sign in the second term and the positive sign in the third term:

LHS = A - 4a + 11 + 9 - 2a

Step 2: Combine like terms:

LHS = A - 6a + 20

Now, we need to compare this with the RHS: 20 - 5a

The identity is true if the LHS equals the RHS for all valid values of 'a'. So, let's compare them:

LHS = A - 6a + 20 RHS = 20 - 5a

Since both the LHS and RHS have the same expression '20', we can focus on the coefficients of 'a':

For the identity to hold true, the coefficient of 'a' in the LHS must be equal to the coefficient of 'a' in the RHS:

Coefficient of 'a' in LHS: -6a Coefficient of 'a' in RHS: -5a

Since -6 is equal to -5, the identity is true for all valid values of 'a'. Therefore, the given expression is an identity.