Answer:
x = -2
y = 5
Step-by-step explanation:
Given two equations
1. 7x + 10y = 36
2. y = 2x + 9
Substitute 2x + 9 for y in equation 1.
We have
7x + 10y = 36
7x + 10(2x + 9) = 36
Distribute 10 into (2x + 9)
We have
7x + 10 x 2x + 10 x 9 = 36
7x + 20x + 90 = 36
27x + 90 = 36
Subtract 90 from both sides to eliminate 90 on the left side
27x + 90 - 90 = 36 - 90
27x = -54
Divide both sides by 27 to isolate x
27x/27 = -54/27
x = -2
Now substitute -2 into either equation to get y
Using equation 2, we have
y = 2x + 9
= 2 x -2 + 9
= -4 + 9
= 5
x = -2
y = 5
Check
7(-2) + 10(5) = 36
Since a stop sign is an octagon it has eight sides. So the perimeter will be:
p=8x, p=perimeter and x=side length. We are told that the perimeter is equal to:
16x^2-80x so we can say:
16x^2-80x=8x subtract 8x from both sides
16x^2-88x=0 factor out 8x
8x(2x-11), since we know x>0
x=11/2
x=5.5 units
Her first rate was faster. The 10 minutes with a change in elevation of -200ft.
In order to solve this you need to have the same minutes. In this problem, I just simply took the 10 minutes and the -200ft and doubled it. Now both rates have 20 minutes. The first rate would have gone -400ft in 20 minutes while the second rate was only -300ft in 20 minutes. I hope this wasn't confusing, and I'm willing to explain more.
Answer:
4x + 1
Step-by-step explanation:
note that (f + g)(x) = f(x) + g(x) , thus
f(x) + g(x)
= x + 3x + 1 ← collect like terms
= 4x + 1
If you rotate about the circumcentre of a regular polygon 72° it will overlap with the original image.