Please help! Question in the picture below!! Will mark brainliest!

Answer:
Exact Form:
3 √7 0 − 6 √ 30
Decimal Form:
−
7.76355265 ...
Hello from MrBillDoesMath!
Answer:
3 sqrt(70) - 6 sqrt(30)
Discussion:
3 sqrt(10) ( sqrt(7) - 2 sqrt(3)) =
3 sqrt(10*7) - 6 sqrt(3*10) =
3 sqrt(70) - 6 sqrt(30)
Not sure if this is what they wanted
Thank you,
MrB