277 years because 831 people/3 people per year = 277 years
Answer:
a = 327 m²
Step-by-step explanation:
Area of bed
r = 22/2 = 11
a = 3.14(11²)
a = 379.94
Area of bed and sidewalk
r = 11 + 4 = 15
a = 3.14(15²)
a = 706.5
Area of sidewalk
a = 706.5 - 379.94
a = 327 m² (rounded to whole number
So for this there is going to be two equations; One showing how much they earned total and one showing how much more Garth made.
Let x mean how much Sandi made and y mean how much Garth made.
The first equation is going to be

The second equation is going to be

.
I'll be using the substitution method since that is already set up for it. So in the first equation substitute y for x+25 since the second equation tells us that is the equivalent to y.
And your equation should look like this:

. From here you can solve for x.
Combine like terms to get

Subtract 25 on each side to get

Divide 2 on each side to get

Now that we had got what Sandi had earned, we can substitute x for 200 in either equation to solve for y. I'll be solving for y in the second equation.

To sum it up, Sandi earned $200 and Garth earned $225.
10xX+15 =11X
10X+15=11X
-10X -10X
15=1X
X=15