Question

na figura PA e PB são segmentos tangentes a circunferência.

Answer 1

A) 3/5 x +10 = 4x -7
10 + 7 =4x - 3/5 x
17 = 3,4 x
x = 17/ 3,4
x = 5           
B) PB= 4.5-7 
PB=20-7= 13 
PB=PA PB=13   PA=13

Answer 2

Sendo PA=PB, temos:
3/5x+10=4x-7
mmc=5
3x+50=20x-35
20x-3x=50+35
17x=85
x=85/17
x=5

PA=3/5x+10
PA=3/5(5)+10
PA=3+10
PA=13

PB=4(5)-7
PB=20-7
PB=13