Answer:
First, we have rounded numbers A and B, and we know that:
A + B = 11000
A - B = 3000
Now we can solve this system of equations as:
Isolating one variable in one of the equations, i will choose A in the second equation:
A = 3000 + B.
Now we can replace this into the other equation:
3000 + B + B = 11000
2*B = 11000 - 3000 = 8000
B = 8000/2 = 4000
and:
A - 4000 = 3000
A = 3000 + 4000 = 7000.
But remember that our original numbers are not exactly whole numbers, they are rounded up, so we could write them as:
A = 6999.8 (that would be rounded up to 7000)
B = 3999.7 (that would be rounded up to 4000)
The sum is:
A + B = 10999.5 (notice that this would be rounded up to 11000)
A - B = 3000.1 (this would be rounded down to 3000)
The middle is zero to the left starting at one go to -5 or whatever the lines stop at (don't forget those are the negative).
Then for the right do the same but positive.
We can see from the diagram that the length of the rectangle is 2 lots of the radius of one quarter circle. The width is made up of one radius, therefore the width is half of the length.
This means that the width of the rectangle is 9cm, and the radius of each quarter circle is 9cm.
To find the shaded area, we find the area of the rectangle and subtract from the areas of each circle, which are equal:
A = lw - 1/2(pi x r^2)
A = 9 x 18 - 1/2(81pi)
A = 162 - 81/2 pi
A = 34.8cm (3sf)
To solve this equation we must use division.
We know we spent 24.32 to fill the gas tank.
And each gallon cost 1.90
We can divide and solve for how many gallons he bought.
24.32 ÷ 1.90 = 12.8
Todd has bought 12.8 gallons of gas.
Good Luck! <3