Cho ΔABC cân tại A có BC = 16cm, đường trung tuyến AM (M∈BC) có độ dài là 6cm. Khi đó AC có độ dài là: * 25 điểm

Plzzz maths ! quadratic sequences=an^2+c 1) 11,17,27,41,59 2) 7,16,31,52,79 3) 6,18,38,66,102 4) 0,9,24,45,72 5) 0,12,32,60,96

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?

Suppose that sahil knows that 45 people with ages of 18 to 29 voted. without using a calculator, he quickly says then 135 people with ages of 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?