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Solve the following simultaneous equations: x+y=9; x-2y+1=1.

Step 1: x+y=7 can be rearranged as: x= 9 - y.Step 2: We substitute the expression of x in the second equation: 9 - y - 2y + 1 = 1Step 3: We calculate the value of y. 9 + 1 - 1- 3y=0. It is equivalent with...

Answered by Daniel T. • Maths tutor

3511 Views

Find the coordinates of the stationary points for the curve y = x^4 - 2*x^2 + 5.

First solve to find dy/dx.dy/dx = 4x^3 - 4xThe stationary points occur when dy/dx = 0. Solve the equation to find the values of x for when dy/dx = 0.4x(x^2 - 1) = 0 x = 0, x = 1, x = -1Finally su...

Answered by Matthew W. • Maths tutor

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120 men and 80 women were asked if they drive to work. Altogether 1/4 of people said yes. And a 1/3 the of men said yes. What fraction of women said yes?

Step 1- Workout how many people overall said yes.
We Know overall there are 200 people and of these 200 people 1/4 said yes. Therefore, we need to workout 1/4 of 200. Simply divide 200 by 4. 200/4=5...

Answered by Harry R. • Maths tutor

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The curve C has equation y = x^3 - 3x^2 - 9x + 14. Find the co-ordinates and nature of each of the stationery points of C.

Step 1: Differentiate y with respect to x. dy/dx = 3x^2 - 6x - 9
Step 2: Equate to zero and solve. 3x^2 - 6x - 9 = 0(x - 3)(x+1) = 0x = 3, x = -1
Step 3: Substitute into original equation to fin...

Answered by Daniel A. • Maths tutor

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Solve algebraically the simultaneous equations, giving your answers in terms of b : 3x+by=5, x-y=-2

First, I would label the two equations 1 and 2:(1) 3x+by=5(2)x-y=-2Next, multiply (2) by 3 and subtract this equation from (1) in order to cancel out the x terms: 3x+by=5-(3x-3y=-6)This results in the equ...

Answered by Thomas L. • Maths tutor

2881 Views