Answer:
158⁰is the answer so follow me
4b^2 - 16 =
4(b^2 - 4) =
4(b + 2)(b - 2)
<em>Greetings from Brasil...</em>
The average for a set of 9 elements will be
(A + B + C + D + E + F + G + H + I) ÷ 9 = 20
Let's make (A + B + C + D + E + F + G + H + I) like S
<em>(I chose S to remember a sum)</em>
Let us think.....
S ÷ 9 = 20
S = 20 × 9
S = 180
So, (A + B + C + D + E + F + G + H + I) = 180
According to the statement, we will include a number (element J) in the sum to obtain a mean of (20 - 4), that is:
<h3>(A + B + C + D + E + F + G + H + I +
J) ÷ 10 = (20 - 4)</h3>
as seen above, (A + B + C + D + E + F + G + H + I) = 180, then
(180 + J) ÷ 10 = 16
(180 + J) = 160
J = 160 - 180
<h2>J = - 20</h2><h2 />
So, including the number - 20 <em>(minus 20)</em> in the original mean we will obtain a new mean whose result will be 16
Answer:
x = 7, x = -3
Step-by-step explanation:
We can find the zeros by factoring the equation using the zero product property.
x^2-4x-21 = 0
(x-7)(x+3) = 0
<u>x-7 = 0</u>
x = 7
<u>x+3 = 0</u>
x = -3
Zeros are x=7 and x= -3.
