What is the value of 2c + 3 when c = 5?
672÷24×18+153-345
what is prime number
how to solve $\sqrt{9}$ × $\sqrt{2}$
3x = 33
3/2 = x + 1/2
1≤3 -2x <5
21/x = 3
When x = 3 and y = 5, find the value of xy
