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!! :)
Answer:
The interest rate is 7.5%
Step-by-step explanation:
You get the difference from the new number and the original. In this case, it is 30.96. I then divided the original by 30.96. The answer turned out to be .15. I doubled checked my answer by timing the original by .15 and adding it. But, I had to divide .15 by 2 so I could get the amount per year. So, it would be 7.5% per year of interest.
I think it is 3.571 but I'm not sure
With 37 mangoes you can bake 12 fruit tarts, because you need 3 mangoes for each tarts and you'll use 
mangoes. The remaining mango is not enough for another tart.
On the other hand, in order to bake 12 tarts, you'll need 24 apples, because you need 2 apples per tart.
So, with 12 apples and 37 mangoes you can bake 12 tart, with one mango as leftover.
