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Solve y = x^2 + 3x + 2 = 0

Factorising gives: y = (x+2)(x+1) = 0. y only equals 0 when (x+2)=0 or (x+1)=0. Therefore x=-2 or x=-1
SL
Answered by Sean L. Maths tutor
3267 Views

Find the stationary points on y = x^3 + 3x^2 + 4 and identify whether these are maximum or minimum points.

Differentiate wrt x. This leaves dy/dx = 3x^2 + 6x and equate this to 0 as we are looking for stationary points.So, 3x^2 + 6x = 0. Factorise to get x(3x +6) = 0. So x = 0 and x = -2 are the two solutions.Now...
TD
Answered by Tutor169411 D. Maths tutor
3514 Views

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

Equation 1: 3x+y= 11, Equation 2: 2x+y=8. You want to find out what x is and what y is.In both equations there is only 1 unit of y therefore it is easiest to rearrange the first equation so that it equals y ...
KM
Answered by Kathryn M. Maths tutor
5185 Views

White paint costs £2.80 per litre and blue paint costs £3.50 per litre. White and blue paint are mixed in the ratio 3 : 2. How much does it cost to make 18 litres of this mixture?

18/(3+2)=3.63x3.6=10.8 2x3.6=7.210.8x2.8=30.247.2x3.5=25.230.24+25.2=55.44
DC
Answered by David C. Maths tutor
3647 Views

Solve the simultaneous equations: y-2x-4=0, 4x^2+y^2+20x=0

Re-arrange y-2x-4=0 to y=2x+4Substitute y=2x+4 into 4x^2+y^2+20x=0 to get 4x^2+(2x+4)^2+20x=0Expand the brackets to get 4x^2+(4x^2+16x+16)+20x=0Simplify to get 8x^2+36x+16=0Divide by 4 to get 2x^2+9x+4=0Fact...
AH
Answered by Andrew H. Maths tutor
8213 Views