Answer:
<u>Answer</u><u>:</u><u> </u><u>4</u><u>x</u><u>²</u><u> </u><u>-</u><u> </u><u>9</u><u>x</u><u> </u><u>+</u><u> </u><u>2</u><u>0</u><u> </u>
Step-by-step explanation:
• General quadratic equation:

• sum of roots → 4 + 5 = 9
• product of roots → 4 × 5 = 20
• substitute:

Step-by-step explanation:
ratio will be
30/27
= 10/9
=10:9
Answer:
4 minutes 5 seconds
Step-by-step explanation:
Without additional information, we have to assume that one sequence can begin immediately after another, and that each takes the same amount of time. The total time for 7 sequences is 7 times the time for one sequence.
7 × 35 seconds = 245 seconds = 4 minutes 5 seconds
__
There are 60 seconds in a minute.
Yes, 23 has an inverse mod 1000 because gcd(23, 1000) = 1 (i.e. they are coprime).
Let <em>x</em> be the inverse. Then <em>x</em> is such that
23<em>x</em> ≡ 1 (mod 1000)
Use the Euclidean algorithm to solve for <em>x</em> :
1000 = 43×23 + 11
23 = 2×11 + 1
→ 1 ≡ 23 - 2×11 (mod 1000)
→ 1 ≡ 23 - 2×(1000 - 43×23) (mod 1000)
→ 1 ≡ 23 - 2×1000 + 86×23 (mod 1000)
→ 1 ≡ 87×23 - 2×1000 ≡ 87×23 (mod 1000)
→ 23⁻¹ ≡ 87 (mod 1000)