14, 21
Step-by-step explanation:
Let the two consecutive multiples be 7n and 7(n+1).
Now, it is given that:
(7n)² + [7(n+1)]² = 637
Simplifying,
49n² + (7n+7)² = 637
49n² + 49n² + 2(7n)(7) + 49 = 637
(as (x+y)² = x² + y² + 2xy)
98n² + 98n + 49 = 637
98n² + 98n - 588 = 0
Dividing by 98 to further simplify,
n² + n - 6 = 0
Factorising, we get
n² + 3n - 2n - 6 = 0
n(n+3) - 2(n+3) = 0
(n+3)(n-2) = 0
Therefore we get n = -3 or n = +2.
Hence, we get the consecutive multiples as 14 and 21.
Feel free to ask if you didn't understand any part.
Hope this helps! :D
Answer:
Step-by-step explanation:
Note that 80% is 8 times 10%.
Thus, we could start with "If 10% of a number is 7" and multiply both quantities by 8: "80% of a number is 56."
Think:
10% of a number is 7,
20% is 14,
50% is 35,
70% is 49, and
80% is 56.
1. The mistake is in the second line (didn't fully distribute)
2. The mistake is in the second line (didn't properly add 4p and 7p)
True!
all parabolas with vertical directrix DO open to the left/right.
