Answer:
<em>(1, - 2) </em>
Step-by-step explanation:
2x - y = 4
3x + y = 1
A = ![\left[\begin{array}{cc}2&-1\\3&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%26-1%5C%5C3%261%5Cend%7Barray%7D%5Cright%5D)
= 2(1) - 3( - 1) =2 + 3 = 5
= ![\left[\begin{array}{cc}4&-1\\1&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D4%26-1%5C%5C1%261%5Cend%7Barray%7D%5Cright%5D)
= 4(1) - 1(- 1) = 4 + 1 = 5
= ![\left[\begin{array}{cc}2&4\\3&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%264%5C%5C3%261%5Cend%7Barray%7D%5Cright%5D)
= 2(1) - 4(3) = 2 - 12 = - 10
<em>x </em>= 
=<em> 1</em>
<em>y </em>= 
= <em>- 2</em>
<em>(1, - 2)</em>
Answer:
x³ + 7x² - 6x - 72
Step-by-step explanation:
Given
(x + 6)(x + 4)(x - 3) ← expand the second and third factor, that is
(x + 4)(x - 3)
Each term in the second factor is multiplied by each term in the first factor, that is
x(x - 3) + 4(x - 3) ← distribute both parenthesis
= x² - 3x + 4x - 12 ← collect like terms
= x² + x - 12
Now multiply this by (x + 6) in the same way
(x + 6)(x² + x - 12)
= x(x² + x - 12) + 6(x² + x - 12) ← distribute both parenthesis
= x³ + x² - 12x + 6x² + 6x - 72 ← collect like terms
= x³ + 7x² - 6x - 72
Answer: x^2 + 9x + 20
Step-by-step explanation:
Foil Method: (a + b) (c + d) = ac + ad + bc + bd
Lets say:
a = x
b = 5
c = x
d = 4
Plugging in the numbers: xx + 4x + 5x + 5*4
Combine like terms:
xx = x^2
4x + 5x = 9x
5 * 4 = 20
You're then left with: x^2 + 9x + 20
It will take 1 minute because if the 100 cats eat 100 fish and they all get the same amount then the rate should 1 fish per cat per minute.....
