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Solve the simultaneous equations: 5x + y = 21 and x - 3y = 9

label equation 5x + y = 21 as (1) and equation x - 3y = 9 as (2) multiply equation (2) by 5 to get : 5x - 15y = 9 (3) then subtract equation (1) from equation (2) in order the eliminate the x variable -1...

Answered by Shruti G. • Maths tutor

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Factorise x^2+3x+2=0

Using the letters a,b and c we label our coefficients by comparing our equation to ax^2+bx+c=0. This means we have; a=1, b=3 and c=2.To factorise a quadratic equation we need to put it into the form (x+

Answered by Daisy A. • Maths tutor

2709 Views

Factorise x^2+6x-27

Label the three coefficients (each number, including an invisible 1 in from of the x²) as a, b and c.Think of it in two parts: a multiplied by c, which is just -27 in this example.The second pa...

Answered by Benjamin G. • Maths tutor

7583 Views

2x + y = 1, x^2 + y^2 = 1

1 : 2x + y = 1 y = 1 - 2x2 : x^2 + (1-2x)^2 = 1 x^2 + (1-2x)(1-2x) = 1 x^2 + 1 - 2x - 2x + 4x^2 = 1 5x^2 - 4x + 1 = 1 5x^2 - 4x = 0 x(5x - 4) = 0 x = 0, x = 4/5 y = 1, y = -3/5

Answered by Josh T. • Maths tutor

2358 Views

Prove that the square of an odd number is always 1 more than a multiple of 4.

Recap, what is 'squaring a number'? Multiplying a number by itself, for example, 3 x 3 = 9. The question hasn't given us a specific number, hence that value can be any number, it is said to be a 'variable...

Answered by Florence O. • Maths tutor

2893 Views