Simplify the radical expression √3(√3 + √12)

STEP 1: Recall what is a radical
https://www.purplemath.com/modules/radicals.htm
STEP 2: Recall what is a radical expression
https://study.com/academy/lesson/radical-expression-definition-examples-quiz.html
STEP 3: Recall what are prime factors of a number
https://www.mathsisfun.com/definitions/prime-factor.html
STEP 4: Recall what is the distributive property in the radical expression
https://www.qalaxia.com/viewDiscussion?messageId=5d37dc6321d531123400cda9
STEP 5: Simplify
Using the distributive property multiply \sqrt{3} with \sqrt{3} and multiply \sqrt{3} with \sqrt{12} to get
\sqrt{3 \times 3} + \sqrt{3 \times 12}
\sqrt{3 \times 3 } + \sqrt{ 3 \times 2\times 2 \times 3}
\sqrt{3 ^{2}}+\sqrt{3^{2} \times 2^{2}} (using the property of exponents - when bases are equal the powers can be added)
3 + \sqrt{(3 \times 2 \times 2 \times 3)}
3 + ( 3 \times 2)
= 3 + 6 = 9