Question #da2fb

1 Answer
Oct 31, 2016

Answer:

#2. 9#
#4. 10#

Explanation:

I'll do questions #2# and #4#.

#2.# We need to factor the numbers within the square roots.

#=>5sqrt(4 xx 3) - 2sqrt(25 xx 3) + 3sqrt(9 xx 3)#

#=>5(2)sqrt(3) - 2(5)sqrt(3) + 3(3)sqrt(3)#

#=>10sqrt(3) - 10sqrt(3) + 9sqrt(3)#

#=>9sqrt(3)#

The numerical coefficient is #9#.

#4.# This is a trinomial factoring problem. When we want to factor a trinomial of the form #y = ax^2+bx + c, a!=1, 0#, we need to find two numbers that multiply to #ac# and that add to #b#.

#=>10r^2 - 8r + 35r - 28#

#=>2r(5r - 4) + 7(5r - 4)#

#=>(2r + 7)(5r - 4)#

The value of #a+ b + c + d# is #2 + 7 + 5 - 4 = 10#

Hopefully this helps!