Question

Simplify (2V5 - 4)(3 V5+2).
a.
4
c.
b.
8-4v5
d. 22-8v5

Answer 1

`(2√(5) - 4)(3√(5)+2)= 22 - 8√(5)`

Explanation:

Given

`(2√(5) - 4)(3√(5)+2)`

Required

Simplify

`(2√(5) - 4)(3√(5)+2).`

Expand brackets

`2√(5)(3√(5)+2). - 4(3√(5)+2).`

Open each bracket

`2√(5)*3√(5)+2√(5)*2 - 4*3√(5)-4*2`

`6 * 5 + 4√(5) - 12√(5) - 8`

`30 + 4√(5) - 12√(5) - 8`

Collect Like Terms

`- 8+30 + 4√(5) - 12√(5)`

`22 - 8√(5)`

Hence:

`(2√(5) - 4)(3√(5)+2)= 22 - 8√(5)`