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Factorise (x^2 +3x-18)=0, solving for x

To factorise and solve this equation we must put it into two brackets, instead of one, each with a single x term. As the is an x^2 term we know there must be an x in each bracket Because the number term at t...
RM
Answered by Rachael M. • Maths tutor
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Solve for simultaneous equations x +5y =9 and 3x + 2y =5.

Here we have 2 unknown variables, x and y. First number the two equations, so x + 5y = 9 is (1), while 3x + 2y = 5 (2). Rearrange both equations so that they become (1) x = 9-5y and (2) x= (5-2y)/3. Next, si...
AL
Answered by Abigail L. • Maths tutor
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Washing powder is sold in two sizes: Bag 1 is 600 grams for £3.30. Bag 2 is 1500 grams and usually costs £9.60 but currently has 15% off. Which is better value?

To determine which is better value, we need to determine the price per gram of each washing powder. Bag 1: For the 600g bag, this is done by dividing the price by the number of grams: 3.30/600 = £0.0055/g or...
JL
Answered by Joe L. • Maths tutor
7072 Views

At what points does the line y = x +1 intersect the circle x^2 + y^2 + 18x + 20y + 81 = 0.

The method we shall use is substitution. We shall replace y each term by 'x + 1' so we are able to obtain an equation in one variable. x^2 + (x+1)^2 + 18x + 20(x+1) + 81 = 0. We now expand the brackets. x^2 ...
HR
Answered by Harry R. • Maths tutor
5874 Views

(2x + 3)/(x-4) - (2x - 8)/(2x + 1) = 1

Multiply through by both denominators, giving us the equation (2x + 3)(2x + 1) - (2x - 8)(x - 4) = (x-4)(2x +1). If we expand the brackets, we arrive at 4x^2 + 8x + 3 - (2x^2 -16x + 32) = 2x^2 -7x -4. If we ...
HR
Answered by Harry R. • Maths tutor
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