2^x+x=11,then what is value of x?

If ,6+6=14
7+7=17
8+8=20 9+9=?

If 2a+5b=12 and ab=3, find the value of 4a^2+25b^2?

The price of pen decreases by 20% then a man can buy 10 more pens for Rs 100. What is the new price ( in Rs) of each pen?

The successive discount of 12%,20% and 25% are equivalent a single discount of?

4^x-8x=0,then what is value of x?

If. 27^x+9^x=150,then find the value of x?

3^n+4^n=91, then find the value of n?