Question

X+x/2+x/4+x\8+...=40

Answer 1

Resposta:

• X + x/2+x/4+x\8+...=40
• a1 = x
• a2 = x/2
• Sn= 40
• q = x/2 : X/1 = x/2 * 1/x = x/2x = 1/2
• q =  x/4 : x/2 = x/4 * 2/x = 2x/4x = 1/2 *
• É uma PG infinita
• Sn =  a1/ ( 1 - q)
• Sn = x / ( 1/1 - 1/2 )
• 40/1 = x/ ( 1/2)
• multiplica em cruz
• 1x = 40 * 1/2
• x = 40/2 = 20 ****
• PG  
• a1 = 20
• a2 = 20 . 1/2 = 20/2 = 10 ***
• a3 = 10 * 1/2 = 10/2 = 5***  
• PG { 20, 10, 5 ......... }