System of equations:
We'll need one equation for the amount of pizzas, and another for the total cost of the pizzas. In this case, x will represent small pizzas, and y will represent large pizzas.
3x + 4y = 100
x + y = 30
Solving the system of equations:
First, we need to solve for one variable in one equation.
x + y = 30
x = 30 - y
Then, we'll take our equation that is solved for x and plug it into the other equation from above.
3(30 - y) + 4y = 100
Next, we solve for y.
90 - 3y + 4y = 100
90 + y = 100
y = 10
Finally, we take our value for y and plug it back in to the very first equation and solve for x.
x = 30 - 10
x = 20
Answer:
The student has sold 10 large pizzas and 20 small pizzas.
Hope this helps!! :)
Noah’s family can wash 21 or fewer loads of laundry before having to add more money to the card
Answer:
54.94 inches
Step-by-step explanation:
First you need to find the radius of the semi-circles within the square.
You find this by dividing the perimeter by 8
64/8 = 8
now use the formula πr^2 to find the area of the semi circle
π8^2 = 201.06
Now find the total area of the square and subtract it from the area of the two semi circles to find the shaded region
16*16 = 256
256-201.06 = 54.94

Write 1 2/3 as an improper fraction...
1 = 3/3. Plus the 2/3 makes 5/3.

To add/subtract fractions, they need the same denominator. (bottom number)
We can change the denominator by multiplying the top and bottom of a fraction by the same number. (it will stay equal, like 1/2 and 2/4)
Let's change 5/3 and 3/4 to a denominator of 12.
5/3 = 20/12 (bottom multiplies by 4, so does the top)
3/4 = 9/12 (bottom multiplies by 3, so does the top)

Now we just subtract the 20 minus 9 twelfths. (the twelfths act as a sort of unit)
(x-h)^2+(y-k)^2=r^2
r=radius
12=r^2
sqrt12=r
2√3=radius