Remember the distributive property? It goes like x(a+b)=xa+xb... For example 3(6+7)=(3*6)+(3*7)=39
Same here
5(3x-6)-8(3x-7)
do the thing
(15x-30)-(24x-56)
Take parentheses off.
15x-30-24x+56
//WHY PLUS 56 NOT MINUS?
//because there was a minus sign outside the original parentheses, so the signs inside have to be flipped when the parentheses is taken off
//Let's simplify now
15x-24x-30+56
-9x+26
^^The answer!
Answer:

Step-by-step explanation:
Answer

Step-by-step explanation:
Let's complete the square
f(x) = x^2 + 6x + 8
y = x^2 + 6x + 8
y-8 = x^2 + 6x
y-8+9 = x^2+6x+9 .... see note below
y+1 = (x+3)^2
y = (x+3)^2-1
note: I added 9 to both sides due to taking half of the 6, and then squaring that result.
We'll restrict x such that
to ensure that this function is one-to-one.
Now we need to swap x and y, and solve for y to get the inverse
y = (x+3)^2 - 1
x = (y+3)^2 - 1
x+1 = (y+3)^2
(y+3)^2 = x+1
y+3 = sqrt(x+1)
y = sqrt(x+1)-3
g(x) = sqrt(x+1)-3 is the inverse
The graph is shown below. The original function is in red. The inverse is in blue. The inverse is the result of reflecting the red curve over the dashed line y = x. So this explains why x and y swap places. Consequently, the domain and range also swap as well.
First setup the system of equations for the given case.
Let sandwich=x
and delivery fee =y
Equations are:
4x+y=33 Equation 1
8x+y=61 Equation 2
Subtract equation 1 from 2.
4x=28
x=7
Now substitute value of x in equation 1.
4(7)+y=33
28+y=33
y=5
So cost of single sandwich=$7 and Delivery fee=$5
Now cost of 12 sandwiches:
12x+y=85
Put y=5
12x+5=85
12x=80
x=6.67 which is less than 7. So, They are not able to get 12 sandwiches for $85.