Answer:
Her electric toothbrush makes 210,000 rotations in one week
Step-by-step explanation:
Note that:
∵ Gerry brushes her teeth for two minutes, twice a day
→ Twice means times 2
∴ Gerry brushes her teeth for 2 × 2 = 4 minutes a day
∵ Gerry's electric toothbrush rotates the brush 125 times per second
∵ 1 minute = 60 seconds
→ Multiply 125 by 60 to find the number of rotating in 1 minute
∴ Gerry's electric toothbrush rotates 125 × 60 = 7,500 in 1 minute
∵ Gerry brushes her teeth for 4 minutes a day
→ Multiply it by 4 to find the number of rotation in 1 day
∴ Gerry's electric toothbrush rotates 7,500 × 4 = 30,000 in 1 day
∵ 1 week = 7 days
→ Multiply the number of rotation in 1 day by 7 to find it in 1 week
∴ Gerry's electric toothbrush rotates 30,000 × 7 = 210,000 in 1 week
∴ Her electric toothbrush makes 210,000 rotations in one week
Answer:
X^2-18x+81
OR
(X-9)^2
Step-by-step explanation:
X(x-9)-9(x-9)=
x^2-9x-9x+81
X^2-18x+81
I don't have a calculator with me, but that should get you going
Answer:
-1/3, -1/4, -3/10, -1/8, -1/16, 1/3, 1/4, 3/10, 1/8, 2/5.
Step-by-step explanation:
-2/5 is -0.4 and 1/2 is 0.5
Ten rational numbers in between are, -0.33333 (-1/3), -0.25 (-1/4), -0.3 (-3/10), -0.125 (-1/8), -0.0625 (-1/16), 0.33333 (1/3), 0.25 (1/4), 0.3 (3/10), 0.125 (1/8), 0.4 (2/5)
