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Sarah’s collection contains dresses, skirts and blouses. If the ratio of dresses to skirts is 7 to 4 and the ratio of skirts to blouses is 7 to 2, what is the ratio of dresses to blouses?

Skirts are common in both ratios. Multiply both ratios by the factors such that skirts are represented by the same number Dresses: skirts = 7: 4 Skirts: blouses = 7: 2 Multiply the first by 7 and the second ...
GW
Answered by Gift W. • Maths tutor
8499 Views

Rationalising the denominator (Surds)

When asked to rationalise simple Surd (square roots that cannot be reduced to a whole number) fractions in the form a/√b we are aiming to remove the surd in the denominator (bottom).-------------------------...
GY
Answered by Galen Y. • Maths tutor
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Find the inverse of f(x) = 7x+4

To start make the equation equal y. So y = 7x+4 Then rearrange the equation to make x the subject. Subtract 4 from both sides: y-4 = 7x Divide by 7: (y-4)/7 = x Now write it in terms of x f(x)^-1 = (x-4)/7 w...
JS
Answered by Joe S. • Maths tutor
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Solve the simultaneous equations: y = 4x^2 - 9x - 1 and y = 5 - 4x

Subtract the second equation from the first, giving you: 4x^2 -5x -6 Factorise the quadratic: (4x + 3)(x - 2) x = -0.75 x= 2 Now substitute these values into one of the equations (or both, just to double-che...
DA
Answered by Damilola A. • Maths tutor
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Solve the simultaneous equations: x^2+y^2=36 ; x=2y+6

Substitute x in terms of y into the first equation: (2y+6) 2 +y 2 =36 Use FOIL to expand the brackets 4y 2 +24y+36+y 2 =36 => 5y 2 +24y=0 y(5y+24)=0 => y=0 or y=(-24)/5 Substitute these values of y int...
DB
Answered by Daniel B. • Maths tutor
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