5a x a = 5a2
5a times 5a would equal 25a^2.
The answer depends upon what the "x" here means. x is commonly used in algebra to denote a variable. However "x" is also a symbol used to mean multiplication. If the first then 5xa means 5 multiplied by x multiplied by a. If the second then 5xa means 5 multiplied by a. This is usually written simply as 5a.
what is 5a x 3 x 2b
5a^(3) if the x means multiplication. 5a^(3)x^(3) if the x is a variable.
5a or 4a squared
5a + 4b - 3a =(5a - 3a) + 4b =2a + 4b =2 (a + 2b)
25a
5a times 3a minus 8a = (5*3)*a2 - 8a = 15a2 - 8a
3a2 - 16a + 5 = 3a2 - 15a - a + 5 = 3a(a -5) - 1(a -5) = (3a - 1)(a - 5)
Since they are like terms, 5a*3a=15a. Find out what "a" is equal to and multiply it by 15. Then, and only then, will you get your answer.
The exponent tells how many times the base is used as a factor. 23 = 2 x 2 x 2