Answer:
(d) 10
Step-by-step explanation:
Multiply by x and divide by its coefficient:
(43.65)(8.79) = (0.4365)(87.9)x
(43.65)(8.79)/((0.4365)(87.9)) = x
At this point, any calculator can give you the answer. It is, perhaps, more satisfying to work out the answer without a calculator.
x = (43.65)/(0.4365) × (8.79)/(87.9)
In the first quotient, the numerator is 100 times the denominator; in the second, the denominator is 10 times the numerator.
x = (100) × (1/10) = 100/10
x = 10
_____
Moving the decimal point to the right 1 place multiplies the numerical value by 10.
Melanie: 15 years old
Kevin: 5 years old
Assume Kevin's present age is x.
That means that 3 years ago, his age would be x - 3.
Melanie's age would be 6(x - 3).
Same thing for 5 years into the future:
Kevin's age would be x + 5.
Melanie's age would be 2(x + 5).
The two equations we have here are:
By subtracting both equations, we are simplified to:
8 = -4x + 28
By solving the equation, we get x = 5.
That means that Kevin's current age is 5 years old.
Melanie's age could be calculated by substituting Kevins'.
6(x - 3) --> 6(5 - 3) --> 12
Since that was 3 years ago, you need to add 3 to 12 to get her current age.
12 + 3 = 15
Melanie's current age is 15 years old.
30: x
60: xsqrt3
90: 2x (hypotenuse)
Answer:
14 % pure juice comes from first brand
Step-by-step explanation:
Mixture:
17 gal 30% contains: 17x 30% = 5.10 gal pure juice
Second brand:
8 gal 48% contains: 8x40% = 3.84 gal pure juice
5.10 − 3.84 = 1.26 gal
1.26 gal is coming from 9 gal of first brand
The percentage of first brand is:
(1.26/9) x100 = 14 % pure juice.
