X^2 - x = 7
(x - 0.5)^2 - 0.25 = 7
(x - 0.5)^2 = 7.25
(x - 0.5) = +/- sqrt 7.25
x = 0.5 +/- sqrt7.25
solution set is {-2.19, 3.19,}
Answer:
0.78125 pounds
Step-by-step explanation:
the weight of 8 brick is 6.25 pound
divide the weight by 8 to take the weight for the one brick
let the time taken to be filled by both pipes be y
1/2 +1/8=1/y
(4+1)/8=1/y
5/8=y
cross multiplying
5y=8
y=8/5
=1.6hrs
Use the Pythagoras theorem:-
height = sqrt(5^2 - 3^2 ) = sqrt16 = 4 metres Answer.