Simplify the following: 1.√7 × √7
2.√18 × √2
3.√45
4.√50/5
5.2√2 × 4√5
6.√48 - √12
7.(2-√3) (1+√3))

1.  √7 × √7  = √[7×7] = √[7²] = 7

2. √18 × √2  = √[18×2] = √36 = √[6²] = 6

3. √45  = √[9×5] = √9 × √5 = √[3²] × √5 = 3√5

4.

5. 2√2 × 4√5  = (2×4) × (√2×√5) = 8×√[2×5] = 8√10

6. √48 - √12  = √[16×3] - √[4×3] = √16×√3 - √4×√3 = 4√3 - 2√3 = 2√3

7. (2 - √3)(1 + √3) = 2×1 + 2×√3 + (-√3)×1 + (-√3)×√3 =

                                     = 2 + 2√3 - √3 - √[3×3] = 2 + √3 - 3 = √3 - 1

i just took the test, the correct answer is .. 31.5 in.