The problem uses the concept of Combination where there are number of members chosen from a group and there order is not important. Thus, the expression that would best describe the given above is 30C6 which means the combination of 30 taken 6. The numerical value for this is 593775.
3rd one 10 x 6 x 6
hope this is right
Answer:
x + x + x + x is the same as 4x
because its "x four times"
5x and x+5 are not the same because x+5 in not "x five times"
5x is 5 multiplied by x.
x + 5 is 5 added to x.
Using Pythagorean triplete






Now




