Un elevador de taller mecánico tiene pistones de entrada y salida (el de levantamiento) de 10cm y 40cm de radio respectivamente. Con este dispositivo se mantiene levantado un auto de 2000kg de masa. a) ¿Cuál es la fuerza aplicada al pistón de entrada?
b) ¿Cuánta presión se ejerce sobre el pistón de salida?

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

you have orange juice on wednesday. (idk why this is the answer)

step-by-step explanation:

1) the property is   ixi = a ⇔x = a   o x = -a

4(x-5)+3= 15⇒4x-20+3 = 15⇒4x-17= 15⇒4x = 15+17⇒4x = 32⇒x =32/4= 8

4(x-5) +3= -15⇒4x-20 +3 = -15⇒4x-17= -15⇒4x =-15+17⇒4x = 2⇒x =2/4= 1/2

the values are x =8 and x = 0,5