Questions asked by MG

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• 40g of NaOH is added to water to create 1 L of solution. The resulting solution has a SG of 1.07. a) Calculate the mass (in lb) of 1 L of solution? b) Calculate the molecular mass of NaOH? c) Calculate the molarity of NaOH in the solution.?
  
• Calculate the weight proportion of H2O in Na2S2O2.5H2O?
  
• The solubility of manganese(II) sulphate at 20oC is 62.9g/100g H2O. How many grams of manganous(II)sulphate penta-hydrate crystal must be added to 51L H2O to make a saturated solution?
  
• Sec theta = 2 to rectangular coordinates??
  
• How do I express #(2^x)-1=2/(2^x)# as a quadratic equation, and show that only one real solution, #x=1#, exists?
  
• If #3^m = 2 and 4^n =27#, show by laws of indices that #m xx n =3/2#??
  
• X=xoe^-(bwt)*(cos(wt)+b/(sqrt(1-b)sin(wt)). units of x is mm, t in s. What are the units of w and b?
  
• Rationalise Denominator: 1/(1 + √2 + √3) by using: (1 - √2 + √3) as conjugate?
  
• 16y^2-x^2-6x-9. How can I factorise this? I know that -(x^2+6x+9) is equal to -(X+3)^2, and 16y^2 can be written as (4y)^2 but I can't quite get the solution (4y-x-3)(4y+X+3)
  
• Can you write #(a+b)^0.5 - (a-b)^0.5# as the square root of a difference?
  
• Vector A, |A| = 44m @ 28° to + x-axis, and Vector B, |B| = 26.6m @ 124° to the + x-axis. Determine the magnitude and direction of R = B - 2A ??
  
• A car with speed #v = "20 ms"^(-1)# passes a stopped police car. Right at this point, the car accelerates at #"2 ms"^-2# and the police car at #2a#. Show that, when the police car catches up to the other car, the distance is #d=(4v^2)/a#?
  
• |x^2 - 2| < 1 Please can anyone help? How to solve this absolute value problem?
  
• Can someone please help me with this absolute value inequality, can I draw a graph for it? #|(x+4)/(x+2)|<=1#?
  
• Show that: #nCr = n-1Cr + n-1Cr-1# ??
  
• For the circle, #(x+1)^2+(y+2)^2=25# What is the length of the tangent to the circle from the point #(6,4)#?
  
• Find the equation to the circle such that the points #A(-3,5)# and #B(4,-2)# form the ends of a diameter?
  
• For what values of #m# is line #y=mx# tangent to the hyperbola #x^2-y^2=1#?
  
• I get a solution of #y=3# but how to solve for this limit?? #lim(x->-4)(3x+12)/(x+4)#
  
• Question 3 part 2 and 3 please?