Answer: $129
Step-by-step explanation:
Answer:
the right system is:
2x - 5y= -5
14x+ 5y = -5
Explanation:
2x - 5y= -5 (1)
14x+ 5y = -5 (2)
(1)+(2)→ 16x=-10 then x= -10/16 = -0.625 ≈ -0.6
Now ,Using equation (1) x = -0.625 then y = 0.75 ≈ 0.8
Answer:
x ≈ 4.19180
Step-by-step explanation:


Divide both sides by 2log (3) to isolate x by itself

or x ≈ 4.19180
using a calculator you can write the answer as a rounded number
From the setup of the problem, the "length of the top of the bookcase, measured along the attic ceiling" will be the hypotenuse of a right triangle, the length "AB". We have both the angle between AB and AC and the length of AC (3.24 meters), so we can use trigonometric identities.
The cosine of the 40 degree angle between AB and AC is equivalent to the length of AC divided by the length of AB. Equivalently, we have:

where "h", the hypotenuse, is the length we want. Rearranging the formula to solve for h we have that

which is 4.2295... meters. Converting to centimeters (multiplying by 100) we have that h = 422.95... centimeters, or if we round the value, h = 423 centimeters.
243.9 tenth
243.88 for hundredth
240 for ten
200 for hundred