Question

 1)$( sin 60 + tg 30 ) ^{-2} * \sqrt{4 \frac{49}{144} }$
2) deplasandu-se cu viteza v un autovehicul parcurge o distanta in 6 ore. Daca viteza se micsoreaza cu 25 % , in timp ce va parcurge distanta respectiva?
va rog , ajutati-ma

Answer 1

1) sin 60= √3/2

tg30= 1/√3=  √3/3

( √3/2 +√3/3) ^ -2 * √625/144

(3√3+2√3)/6 ^-2 *25/12=

=( 5√3/6) ^ -2 * 25/12=

= 1/(5√3/6)² * 25/12=

= 36/75 *25/12=

=3/3=1

2)V=d/t

d=V*t

t=d/V

t=6h

25% din V=25/100 *V= 1/4*V=  V/4  se reduce

V-V/4=  (4V-V)/4=  3V/4  -restul

V.........6h
3V/4.....x

x=  V * 6/3V/4

x= V*6 * 4/3V

x= 2*4

x=8h