The surface area of this figure is __<u>310</u>__ square centimetres.
Answer:

Step-by-step explanation:
First, multiply the two denominators together to get the shared denominator, which will allow you to actually subtract the two numbers. 4 × 8 = 32, so the shared denominator will be 32.
Then, cross-multiply. 11 × 8 = 88, so
becomes
. 3 × 4 = 12, so
becomes
.
Now, you can subtract. 
Finally, simplify.
. The final difference is
.
The value of m is 12 6/7.
Explanation:
To find m, we want one m instead of 7, so we divide both sides by 7. 7m/7 = 90/7, which would be m = 12 6/7.