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3 years ago

Solve each equation mentally.

Mathematics

2 answers:

motikmotik3 years ago

7 0

16. 4 (9*4=36)
17. 6 (6*11=66)
18. 8 (10*8=80)
19. 9 (9*5=45)
20. 48 (4*12=48)
21. 13 (13*2=26)

andreyandreev [35.5K]3 years ago

4 0

16.4
17.6
18.8
19.9
20.48
21.13

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Answer:

The answer is:

30 minutes.

Step-by-step explanation:

We are given the following information:

at 160 m/min, tool life = 5 min.

at 120 m/min, tool life = 17 min.

This means that as the speed reduced from 160 m/min to 120 m/min, the tool life increased from 5 min. to 17 min, hence the difference between the changes are:

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40 m/min = 12 min

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3 years ago

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Lorico [155]

Answer:

Given that the question rightly asks the amount it cost to drive from Smithville to Jones City, we have;

The question rightly asks the amount it cost to drive from Smithville to Jones City is approximately $7.209

Step-by-step explanation:

The coordinates of Smithville is (-25, 10)

The coordinates of Jones City is (15, 12)

The cost of driving a car for a mile = $0.18

Therefore, the distance from Smithville to Jones City is given by the formula for the distance, l, between two points with coordinates as follows;

$l = \sqrt{\left (y_{2}-y_{1} \right )^{2}+\left (x_{2}-x_{1} \right )^{2}}$

Where;

(x₁, y₁) = (-25, 10) and (x₂, y₂) = (15, 12)

$l = \sqrt{\left (12-10 \right )^{2}+\left (15-(-25) \right )^{2}} = 2 \cdot \sqrt{401}$

The distance from Smithville to Jones City = 2·√401 ≈ 40.05 miles

The amount, A, it cost to drive from Smithville to Jones City a distance of approximately 40.05 miles is therefore given as follows;

A = 40.05 miles × $0.18 ≈ $7.209

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