I’m assuming that 9cm is the hypotenuse of the triangle.
By using Pythagorean’s theorem
α²+b²=c²
in this case, c =9
So, (x+5)² + (x-3)² =(x+5)(x+5) + (x-3)(x-3)
=x²+5x+5x+25+x²-3x-3x+9
=2x²+4x+31=81
And by solving the equation, you get two x values, but since you can’t have x as a negative figure, the positive figure being 3.9498, x=3.95 (corrected to 3 significant figures)
(8+r)4
= 4*8+ 4*r (distributive property)
= 32+ 4r
8(x+9)
= 8*x+ 8*9
= 8x+72
Answer:
a) Between 74 and 90
b) 81.86% of the scores are between 78 and 90
Step-by-step explanation:
a) According to the Empirical Rule, in a normal distribution, 95% of the data are within 2 standard deviations of the mean. Therefore, the range that 95% of the scores fall in is between 82-4(2)=74 and 82+4(2)=90.
b) The percent of scores that are between 78 and 90 is: normalcdf(lower,upper,μ,σ) = normalcdf(78,90,82,4) = 0.8185946784 ≈ 0.8186, or about 81.86% of the scores.
the answer is C. Expanding Gases :D