80, 84, 79, 44, 87, 73, 89, 90, 82, 89, 93, 97, 77, and 71 whats the mean
Contact [7]
Answer:
sum up the numbers and divide by the numbers of values.
80+84+79+44+87+73+89+90+82+89+93+97+77+71 / 14
1135/14
= 81•1 is the mean
13 ESSA É A RESPOSTA CORRETA DA SUA PERGUNTA.
Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution
2x^2 + 4x + 1 = 0
2x^2 + 4x + 1 - 1 = 0 - 1
2x^2 + 4x = -1
X(2x + 4) = -1
X = -1.
2x + 4 = -1
2x + 4 - 4 = -1 - 4
2x = -5
2x/2 = -5/2
X = -5/2.
I believe these are the solutions. If not you can use the quadratic formula to solve for the roots, solutions.
