You have the following expression:
-9√98
If you don't use a factor tree, then, you can express the number 98 as follow:
98 = 2*49
moreover, consider that 49 = 7*7 = 7^2,
then, 98 can be written as follow:
98 = 2*7^2
Now, consider that the square root of a product is the product of the square roots, then, you have:
√98 = √(2*7^2) = √(2)*√(7^2) = 7√2
Hence, you can write the original expression as follow:
-9√98 = -9*7√2 = -63√2
answer: -63√2
