Answer:
3:4 9:12
Step-by-step explanation:
Rewrite the ratios as fractions. 3:4 becomes 3/4, and 9:12 becomes 9/12, which simplifies to 3:4. Therefore A is a true proportion.
Answer: 126
Step-by-step explanation: 14 x 9 is 126, so its 126!!
Answer:
In Exercises 1-15 use mathematical induction to establish the formula for n ≥ 1.
1. 1
2 + 22 + 32 + · · · + n
2 =
n(n + 1)(2n + 1)
6
Proof:
For n = 1, the statement reduces to 12 =
1 · 2 · 3
6
and is obviously true.
Assuming the statement is true for n = k:
1
2 + 22 + 32 + · · · + k
2 =
k(k + 1)(2k + 1)
6
, (1)
we will prove that the statement must be true for n = k + 1:
1
2 + 22 + 32 + · · · + (k + 1)2 =
(k + 1)(k + 2)(2k + 3)
6
. (2)
The left-hand side of (2) can be written as
1
2 + 22 + 32 + · · · + k
2 + (k + 1)2
.
In view of (1), this simplifies to:
To find the surface area of the rectangular prism, use the formula:
A=2(wl+hl+hw)
Note that: w = 4, l = 12, h = 3
plug into the equation
A = 2((4)(12) + (3)(12) + (3)(4))
Simplify
A = 2(48 + 36 + 12)
A = 2(96)
Multiply
A = 96 x 2
A = 192
192 m³ is the surface area of the rectangular prism.
hope this helps
Answer:
642 mm or 64.2 cm
Step-by-step explanation:
67cm-28mm
We need the same units
67 cm * 10 = 670 mm
670 mm - 28 mm
642 mm
We can convert back to cm by dividing by 10
64.2 cm