Answer: 
Step-by-step explanation:
The first thing you must remember is the mulplication of signs. You know that:
You can observe that the number inside the parentheses is positive (+) and the sign that is outside the parentheses is negative (-), therefore, when you multiply these signs you get a negative sign (-). Then you get:
Now, you need to add these numbers. And the result obtained is:
Answer:
There are 24 green marbles.
Step-by-step explanation:
Let x be the number of green marbles, then:
3/2 = 36/x
3x = 2*36
3x = 72
x = 24.
Answer:
x=54
Step-by-step explanation:
easy
180 is a triangle
so
exterior+interior=180
so 180-123
57
now add all up to 180
180=57+x+69
x=54
Answer:
true true flase
Step-by-step explanation:
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>
