Let n be old painters time. Then the new painters are 2n. So:
1/n+1/2n=1/6
2+1=2n/6
2n=18
n=9
The old painters take 9 hours; the new ones take 18
☺☺☺☺
Answer:
Step-by-step explanation:
1) Eliminate parentheses:
0.1x +18.8 = -4 +2x
22.8 = 1.9x . . . . . . . . . add 4 - 0.1x
12 = x . . . . . . . . . . . . . divide by 1.9
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2) Eliminate parentheses:
-16 +4x = 0.8x +12.8
3.2x = 28.8 . . . . . . . . add 16 - 0.8x
x = 9 . . . . . . . . . . . . . .divide by 3.2
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<em>Comments on the solutions</em>
The expression we add in each case eliminates the constant on one side of the equation and the variable term on the other side. That leaves an equation of the form ...
variable term = constant
We choose to eliminate the smaller variable term (the one with the coefficient farthest to the left on the number line). Then the constant we eliminate is the on on the other side of the equation. This choice ensures that the remaining variable term has a positive coefficient, tending to reduce errors.
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You can work these problems by methods that eliminate fractions. Here, the fractions are decimal values, so are not that difficult to deal with. In any event, it is good to be able to work with numbers in any form: fractions, decimals, integers. It can save some steps.
Answer:
Step-by-step explanation:
1= 2/3
2=5/6
3=21/40
4= 2 11/20
5= 1 1/3
6=5/6
7=1 1/2
8=9/10
9= 5 1/6
10= 2 1/2
Answer:
Exact area: 39.2π cm²
Approximate area: 123.2 cm²
Step-by-step explanation:
The area of a circle is πr².
A full circle can be thought of as a sector of a circle with 360° of central angle. For a sector of a circle with a central angle of n°, multiply the area of the circle by the fraction n°/360°.
The formula for the area of a sector of circle with central angle n° and radius r is
A = (n°)/(360°) × πr²
Here we have n = 72; r = 14 cm
A = (n°)/(360°) × πr²
A = (72°)/(360°) × π × (14 cm)²
A = 39.2π cm² = 123.2 cm²
Answer: Swing twice as fast
Explanation: If superman wants to get a lot of kinetic energy he should swing fast. Kinetic energy is the energy of motion/movement so that means the more you do something fast the more KE you will get and if you do something twice as fast then you will gain more kinetic energy.
