You can think in reverse. Addition is the opposite of subtraction. So to solve 15-8, you can ask "8 plus what number is equal to 15?" and note how 8+7 = 15. So that's why 15-8 = 7. Similarly, 15-7 = 8 can be solved the same way.
Tenemos que
R------------ > recorrido total
x---------------- > viaje en tren--------------- > (1/2)*R
y----------------- > viaje en bicicleta-------------(1/2)*(1/3)*R=(1/6)*R
z------------------- > viaje en automovil --------- > (1/2)*(2/3)*R=(2/6)*R=100 km
R=x+y+z
resolviendo nos queda que
(2/6)*R=100--------------- > R=100*6/2=300 km
viaje en tren----------- > (1/2)*R=300/2=150 km
viaje en bicicleta------- > (1/6)*R=300/6=50 km
( estos dos ultimos calculos no lo estan pidiendo y no hacen falta para contestar la pregunta, simplemente se realizan a manera didactica)
La respuesta es
La distancia entre las dos ciudades es de 300 km
Do you want the equation of the line given the slope and a point it goes through?
y - y1 = m (x - x1)
y - 16.5 = 1.75 (x - 10)
y - 16.5 = 1.75x -17.5
y = 1.75x - 1
Multiply 3x9 and it gives u 27
And -3 plus -9 equal -12
25.75% say no- 206/80 then * 10 (x)
74.25% say yes- 100-x