Add and Subtract Radicals Quick Check
Math 8 Q2 (Pre-Algebra) / Roots and Irrational Numbers
add 3 square root 21 + 7 square root 21
10 square root 21
10 square root 42
square root 52
square root 24 + square root 28
what is the answer
The answer is: square root 52
To simplify the expression "3√21 + 7√21," you can combine the like terms (terms with the same radical). In this case, the like terms are both numbers multiplied by the square root of 21.
3√21 + 7√21 = (3 + 7)√21 = 10√21
Hence, the simplified expression is 10√21.
For the expression "√24 + √28," we cannot combine the radicals as they are not like terms. However, we can simplify each radical individually.
√24 can be simplified as √(4*6), which is equal to 2√6.
Similarly, √28 can be simplified as √(4*7), which is equal to 2√7.
Therefore, the expression "√24 + √28" simplifies to 2√6 + 2√7.
To add or subtract radicals, you need to combine like terms. In this case, both expressions have a square root of 21.
To add or subtract these terms, you simply add or subtract the coefficients in front of the square root of 21.
For the first expression, 3 square root 21 + 7 square root 21, the coefficients are 3 and 7. Adding these together gives us 10. So the answer is 10 square root 21.
The correct answer is: 10 square root 21.