Resolver left(2a+3right)left(2a-3right)+left(9a+bright)left(9a-bright)

$$\left( 2a+3 \right) \left( 2a-3 \right) + \left( 9a+b \right) \left( 9a-b \right)$$

Ebaluatu

$$85a^{2}-b^{2}-9$$

Ebazpidea

Kasurako: \left(2a+3\right)\left(2a-3\right). Biderketa karratuen desberdintasun bihur daiteke arau hau erabilita: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.

$$\left(2a\right)^{2}-3^{2}+\left(9a+b\right)\left(9a-b\right)$$

Garatu \left(2a\right)^{2}.

$$2^{2}a^{2}-3^{2}+\left(9a+b\right)\left(9a-b\right)$$

4 lortzeko, egin 2 ber 2.

$$4a^{2}-3^{2}+\left(9a+b\right)\left(9a-b\right)$$

9 lortzeko, egin 3 ber 2.

$$4a^{2}-9+\left(9a+b\right)\left(9a-b\right)$$

Kasurako: \left(9a+b\right)\left(9a-b\right). Biderketa karratuen desberdintasun bihur daiteke arau hau erabilita: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.

$$4a^{2}-9+\left(9a\right)^{2}-b^{2}$$

Garatu \left(9a\right)^{2}.

$$4a^{2}-9+9^{2}a^{2}-b^{2}$$

81 lortzeko, egin 9 ber 2.

$$4a^{2}-9+81a^{2}-b^{2}$$

85a^{2} lortzeko, konbinatu 4a^{2} eta 81a^{2}.

$$85a^{2}-9-b^{2}$$

Zabaldu

$$85a^{2}-b^{2}-9$$

Ebazpidea

Kasurako: \left(2a+3\right)\left(2a-3\right). Biderketa karratuen desberdintasun bihur daiteke arau hau erabilita: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.

$$\left(2a\right)^{2}-3^{2}+\left(9a+b\right)\left(9a-b\right)$$

Garatu \left(2a\right)^{2}.

$$2^{2}a^{2}-3^{2}+\left(9a+b\right)\left(9a-b\right)$$

4 lortzeko, egin 2 ber 2.

$$4a^{2}-3^{2}+\left(9a+b\right)\left(9a-b\right)$$

9 lortzeko, egin 3 ber 2.

$$4a^{2}-9+\left(9a+b\right)\left(9a-b\right)$$

Kasurako: \left(9a+b\right)\left(9a-b\right). Biderketa karratuen desberdintasun bihur daiteke arau hau erabilita: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.

$$4a^{2}-9+\left(9a\right)^{2}-b^{2}$$

Garatu \left(9a\right)^{2}.

$$4a^{2}-9+9^{2}a^{2}-b^{2}$$

81 lortzeko, egin 9 ber 2.

$$4a^{2}-9+81a^{2}-b^{2}$$

85a^{2} lortzeko, konbinatu 4a^{2} eta 81a^{2}.

$$85a^{2}-9-b^{2}$$