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For a quadratic to have equal roots, the value of the discriminant (b²-4ac) =0. This means that the quadratic formula yields only one result (or two equal roots), since x=(-b ±0)/2a , thus if a...

If you have a fraction where the denominator is a surd, such as 5/(1+sqrt(2)), you need to multiply the denominator by another number so that it becomes a a whole number. If you multiply either the denomi...

(3x-5)(x+6)factors of 90 (3x30): 1x90, 6x15, 9x10, 5x18and add up to 13 can only be 5 and 1818-5=13 5/3 or 18/3=6 and 5x6=30so must be (3x-5)(x+6) and check by expanding with FOIL method

£120 is the price of the car after it has been reduced by 20%. This means that £120 is equal to 80% of the original price.2 ways to work this out:1) £120 = 80 % £ ? =100%therefore: £? = (120 x 10...

A bag in a sale is reduced by 20%. It now costs £40. What was the original price? Solution 1: Using ratios and basic percentagesA good way to solve this problem is by thinking about what percentage is lef...