All work is show in the picture below.
Answer:
12 bolt 18 nuts
Step-by-step explanation: (Elimination method)
N=nuts
B=bolts
B + N = 30
0.20B + 0.10N = 4.20
20B+10N=420 (I multiplied by 10 to eliminate decimals
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I will multiply the first by (-10)
-10B -10N =-300
20N +10N=420
10B+0 = 120
B=12 (12 BOLT)
30-12 =18 (8 NUTS)
12*0.20=2.40
18*0.10=1.80
2.40+ 1.80 = 4.20
Answer:
A
Step-by-step explanation:
let r represent rate and d distance.
Given that r varies directly as d² then the equation relating them is
r = kd² ← k is the constant of variation
To find k use the condition r = 4 when d = 15, then
4 = k × 15² = 225k ( divide both sides by 225 )
k = 
r = d² ← equation of variation
When r = 9, then
9 = d² ( multiply both sides by 225 )
2025 = 4d² ( divide both sides by 4 )
506.25 = d² ( take the square root of both sides )
d = 
= 22.5 = 22 
→ A
The answer is <span>Difference of Cubes.
Difference of cubes is </span>a³ - b³.<span>
27 can be written as 3</span>³ (= 3 × 3 × 3 = 27). So, a = 3.
8 can be written as 2³ (= 2 × 2 × 2 = 8). So, b = 2.
Difference of cubes can be expressed as:
a³ - b³ = (a - b)(a² + ab + b²)
⇒ 3³ - 2³ = (3 - 2)(3² + 3×2 + 2²) = 1 × (9 + 6 + 4) = 1 × 19 = 19
⇒ 27 - 8 = 19
