Rate of change = 5
Im positive this is the correct answer
Answer: B. x, in the second equation
Step-by-step explanation:
The given system :
To apply the substitution method , first we need to select the best variable and a equation which is easy to simplify.
From the given system equation (2) have all the numbers which are multiples of 3.
Then we divide 3 on both sides of equation (2), we get
Therefore, the best variable to solve for and from what equation is x, in the second equation.
We know: length of a rectangle is 7m less than three times the width.
So let's set the length to l, width to w.
And we can get that l = 3w-7.
We also know that the area of the rectangle is 66 m^2.
Thus, l*w= 66.
So we have:
function 1: l=3w-7
function 2: l*w=66
plug function 1 to 2.
(3w-7)*w=66
3w^2-7w-66=0
w=6 and -11/3.
And the width of a rectangle can not be negative.
So: w=6.
Plug w=6 back to function 1 or 2, either way is correct and can give you the length. In this case, I will plug it back to function 1.
l=3*6-7=11.
So: the width of the rectangle is 6, and the length of the rectangle is 11.
I believe the answer is C.
575 / 5 = 115
Dora has saved $115 per month.
