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Solve the simultaneous equations: y=3x+2, x^2+y^2=20

y=3x+2 x^2+y^2=20 x^2+(3x+2)^2=20 x^2+(3x+2)(3x+2)=20 x^2+(9x^2+6x+6x+4)=20 x^2+(9x^2+12x+4)=20 10x^2+12x+4=20 10x^2+12x-16=0 5x^2+6x-8=0 (5x-4)(x+2)=0 5x-4=0, x+2=0 x=4/5=0.8, x=-2 y=3x+2, y=3x+2 y=3(0.8)+2...
DC
Answered by Daniela C. • Maths tutor
16030 Views

If a student uses an electric kettle connected to a 230V mains power supply, with a heating power of 1.8kW. Assuming negligable losses, answer the following: a) find the current in the kettle b) find the total energy transferred in 2 minutes of operation

a) The governing equation here is Power = current x voltage or P=IV. using this formula, 1,800 = I x 230 => I=1800/230 = 7.83 A (3sf) b) as watts is equal to joules/seconds, we can find the energy in joul...
CP
Answered by Chris P. • Physics tutor
22107 Views

Using named examples, assess the advantages and disadvantages of top-down and bottom-up development strategies. (15)

Development strategies can be used to help bridge the development gap between the rich and poor. These strategies can be successful if they help improve the standard of living. Different strategies take diff...
EB
Answered by Ella B. • Geography tutor
50311 Views

Find the modulus-argument form of the complex number z=(5√ 3 - 5i)

The easiest way to complete questions of these types is to first sketch an Argand diagram. With 5√ 3 on the x (real) axis and -5 on the y (imaginary) axis, the modulus would be calculated simply by using pyt...
CP
25505 Views

3x^2 + 7x - 13 = 0. What is x?

By using the quadratic quation, it can be deduced that x = 1.22 or x = -3.55
MS
Answered by Miranda S. • Maths tutor
5875 Views