Answer:
Step-by-step explanation:
THe sides are the same length
11=x+5
x=6
y=mx+b is the equation of a line;
m=slope , b= y-intercept
m=4 ; so we have : y=4x+b
We are give a set of points which it passes through, we can simply plug them in:
-2 = 4(3)+b (3 is the x and -2 is the y)
We get -2 = 12 +b .... -14=b
our final equation is : y=4x-14
$990
550 x .80 = 440
$550 + $440 = $990
The equation would be 6x+x=63. Not sure how the models play out, but good luck
Answer:

Step-by-step explanation:
When adding rational numbers, if the denominator is the same you simply keep the denominator (bottom of fraction) as it is and apply the operation given to the numerator ( top of fraction )
So we have 
==> remove parenthesis and apply signs

==> simplify numerator by combining like terms

and we are done!
Note:
like terms are terms with the same variable and exponent
An example of like terms are 6x^7 and 3x^7 as they have x as a variable and a power of 7
The like terms being combined here were (6x² and 4x²) and (5 and -2)