Question 350074
Please help me solve these equations.I am not sure if my answers are correct.
I have to divide and simplify. 
3√13 + 7√13= 
√90 - √10= 
√75a^3 + a√12a= 
(-5√6) (2√3)= 
(√5 + 4) (√5 – 1)= 
for the first problem the answer I got was=36
3√13 + 7√13= {{{10sqrt(13) = 36.0555}}}
---------------------
√90 - √10= {{{2sqrt(10) - sqrt(10) = 2sqrt(10)}}
=~ 6.32
for the second3problem the answer I got was=6.32
------------------
(-5√6) (2√3)
If they're multiplied:
= {{{-10sqrt(18) = -30sqrt(2)}}}
for the fourth problem the answer I got was= -10sqrt18
----------------------
(√5 + 4) (√5 – 1)= {{{5 - 4 + 3sqrt(5)}}}
= {{{1 + 3sqrt(5)}}}