Answer:
x=2
Step-by-step explanation:
5x+
= 7
5x+4 =7 (2)
5x+4=14
5x=14-4
5x=10
= 
x=2
Answer:
x ≈ - 1.3
Step-by-step explanation:
16x + 20 = 0
16x + 20 - 20 = 0 - 20
16x = - 20
16x ÷ 16 = - 20 ÷ 16
x = - 1.25

- 1.25 rounds to - 1.3
Answer:
36
Step-by-step explanation:
a² + b² = c²
a² + 77² = 85²
a² + 5929 = 7225
a² = 1296
a = 36
Answer:
5000 particles of size 10 nanometer should be stacked
Step-by-step explanation:
Average diameter of the of the human hair = 50 micron = 50 × 10⁻⁶ m
Now,
let the number of 10 nanometer i.e 10 × 10⁻⁹ m particle be 'n'
thus,
n × 10 × 10⁻⁹ m = 50 × 10⁻⁶ m
Therefore to find the number of 10 nanometer i.e 10 × 10⁻⁹ m particle,
n = 
or
n = 5000
Hence,
5000 particles of size 10 nanometer should be stacked