Question

Dadas as expressões A = -a² – 2a + 5
e B = b² + 2b + 5:

A) Se a = 2 e b = -2, entao A + B
B) Se a = 2 e b = 2, entao A - B

Answer 1

A) A + B

A = –2² – 2×2 + 5
A = –4 – 4 + 5
A = –8 + 5
A = –3

B = (–2)² + 2×(–2) + 5
B = 4 – 4 + 5
B = 5

A + B = (–3)+5
A + B = 2

b) A – B

A = -2² – 2×2 + 5
A = – 4 – 4 + 5
A = – 8 + 5
A = – 3

B = 2² + 2×2 + 5
B = 4 + 4 + 5
B = 13

A – B = – 3 – 13
A – B = – 16

Answer 2

Bom dia

Dadas as expressões
A = -a² – 2a + 5 
B = b² + 2b + 5: 

A) Se a = 2 e b = -2, entao A + B 

A = -a² – 2a + 5 
A = -4 - 4 + 5 = -3

B = b² + 2b + 5: 
B = 4 - 4 + 5 = 5

A + B = -3 + 5 = 2

B) Se a = 2 e b = -2, entao A - B  (b=-2 correçao de autor)

A =  -a² – 2a + 5 
A = -4 - 4 + 5 = -3

B = b² + 2b + 5: 
B = 4 - 4 + 5 = 5

A - B = -3 - 5 = -8