Question

1.Oblicz :

x/(10+x)=tg30°

Answer 1

x/(10+x)=tg30°    zał. x ≠ -10

x/(10+x)= √3 / 3    mnożymy na "krzyż"

3 * x = √3 * (10 + x)

3x = 10√3 + √3x 

3x - √3x = 10√3

x(3 - √3) = 10√3

x = 10√3 / (3 - √3)

x = [10√3 *(3 + √3) ] / [ (3 - √3)*(3 + √3)] 

x = [10√3*(3 + √3)] / (9 - 3)

x = (30√3 + 30) / 6

x = 6(5√3 + 5) / 6

x = 5√3 + 5