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Solve the simultaneous equations 3x - y = 5, x + 2y = -3

3x - y = 5 (A), x + 2y = -3 (B),6x - 2y = 10 (2A) ,7x + 2y +- 2y = 7 (2A) + (B),7x +2y - 2y = 7,7x = 7,x = 1,Sub x=1 -> (A),3(1) - y = 5,3 - y = 5,-y = 2,y = -2 ,x = 1, x= -2
JC
Answered by Jessica C. • Maths tutor
5430 Views

What is the co-ordinates of the minimum point of the quadratic equation x^2+6x-16?

Well this can be rewritten as : (x+8)(x-2), so roots are x=-8, and x=2. So therefore the x co-ordinate of the minimum point is half way between the 2 roots by symmetry. So the x co-ordinate is x=-3. Substitu...
LO
Answered by Lance O. • Maths tutor
3637 Views

A group of 55 students were asked if they had a cat or a dog. 11 were known to own both, 18 said they owned only a dog, and 34 said they owned at least a cat. Give the probability that a student has neither as a fraction in its simplest form.

ANSWER = 3/55
ER
Answered by Emily R. • Maths tutor
3069 Views

Solve the simultaneous equations: 3x+y=11 and 2x+y=8.

First we want to eliminate of one these variables in order to solve the equations. We need to identify which variable has the same coefficient- in this case, it is y. So, we subtract the two equations from e...
SK
Answered by Simran K. • Maths tutor
7037 Views

Find the equation to the tangent to the curve x=cos(2y+pi) at (0, pi/4)

Normally to find a tangent we want to work out dy/dx, but since this equation is x=something, it's much easier to work out dx/dy first, then we get dy/dx by doing 1/(dx/dy)=dy/dx. By the chain rule, dx/dy = ...
SJ
Answered by Sarah J. • Maths tutor
11654 Views