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x²-9x+20=0x²-5x-4x+20=0x(x-5)-4(x-5)=0(x-4)(x-5)=0x-4=0x=4x-5=0x=5

In order to tackle questions like this with two letters of unknown value, first what we try to do is eliminate one of the variables completely from an equation. If we call 6a + b = 16 eqn 1 and 5a - 2b = ...

(x+1)(x+2) = ( x^2 + 3x + 2) - multiplying out the first 2 terms(x^2 + 3x + 2)(x + 3) = x^3 + 3x^2 + 2x + 3x^2 + 9x + 6 - multiplying the product of the first two terms by the last termx^3 + 6x^2 + 11x + ...

To solve this question we need to find the values of x which work for the equation x^(2) + 4x + 4 = 0. To solve the equation we can factorise the left-hand side into brackets which will m...

Remember we can multiply both sides of an equation by the same thing without changing the meaning of the equation. Multiplying equation 1 by 2 gives 4x+6y=6 and multiplying equation 2 by 3 gives 9x+6y=21 ...