Answer:
9cm
Step-by-step explanation:
- Since PQST is a rectangle, ∠QST=∠QSR=∠90º. So triangle QSR is a right triangle.
- By the Pythagorean Theorem and that SR=6 and QR=10, we can say that 6^2+b^2=10^2. So, 36+b^2=100. And b^2=64 and b=8. So QS=8.
- Now we know that QS=PT=8.
- By the Pythagorean Theorem and that PR=17 and PT=8, we can say a^2+8^2=17^2. So, a^2+64=289. And a^2=225 and a=15.
- We know that TR=15 and SR=6 and TR-SR=TS, so 15-6=9.
For this case we must simplify the following expression:
We eliminate the parentheses taking into account that:

So:

We add similar terms taking into account that:
Equal signs are added and the same sign is placed.
Different signs are subtracted and the major sign is placed.

Answer:

The answer is 30, assuming it is a cube,
First differences are -9, +18, -8, +16, suggesting that the next ones will be -7, +14.
Hence, the next two terms might be expected to be 13, 27.
If 20 large cakes are needed, you'll need 4 helpers. To find this, you first need to find how many cakes 1 helper can make. Every hour, one helper can make 2 large cakes. If they have the kitchen for 3 hours, 6 large cakes can be made by one helper. This also means that 2 helpers make 12 cakes, 3 helpers can make 18 cakes, and 4 helpers can make 24 cakes. Since you can't have a fraction of a helper, 4 is your answer. For the 700 small cakes, you do the same thing. Every hour, 1 helper makes 35 small cakes. In 3 hours, 1 helper can make 105 small cakes. 2 can make 210, 3 can make 315, 4 can make 420, 5 can make 525, 6 can make 630, and 7 can make 735. The 700 small cakes takes 7 helpers and the 20 large cakes takes 4 helpers. Your total amount of helpers is 11.