tolong dijawab ya makasih semuanya.

1. 9√7 x 3 √4x7 = 9√7 x 6√7 = 9 x 6 x 7 = 378

2. 5x3+5√50=15+5√25x2=15+25√2 =5(3+5√2)

3. (√5 + √6)(√5 + √6) = 5+6+2√30 = 11+2√30

4. (√28 - √12) (2√7 + 2√3)
= 2√28x7 + 2√28x3 - 2√12x7 - 2√12x3
= 2√4x7x7 + 2√4x7x3 - 2√3x4x7 - 2√4x3x3
= 2√169 + 2√4x21 - 2√4x21 - 2√36
= 2x14 + 2x2√21 - 2x2√21 - 2x6
= 28 + 4√21 - 4√21 - 12
= 28 - 12 = 16

maaf klo salah