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How can I solve quadratic equations by completing the square?

When we have a quadratic (ax²+ bx + c = 0) we can "complete the square" to solve for x. For example x²+ 8x + 7 = 0. First look at the x²+ 8x, in particular th...

Answered by Thomas B. • Maths tutor

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Find the value of X and Y if X^2 + Y^2 = 13 and 2X + Y = 1

Firstly, since only one equation is linear, substitution must be used. This will allow us to make a quadratic equation with one variable and solve for X and Y. To do this, I will make Y the subject of the...

Answered by Alexis S. • Maths tutor

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A t-shirt is in the sale section of a store. It has 20% off and the new sale price is £12. What was the original price of the t-shirt?

Original Price x Percentage Multiplier = New Price

Percentage Multiplier = (100-20)/100 = 0.8

OP x 0.8 = £12

OP = £12/0.8 = £15

Answered by Katy B. • Maths tutor

3329 Views

Find the Lowest common multiple of 96 and 132

First, split into prime factors- 96= 2^5 * 3 and 132= 2^2 * 3 * 11 Whilst very similar to highest common factor, lowest common multiple is found by comparing the two sets of prime factors, and for each pr...

Answered by Alex W. • Maths tutor

3165 Views

There are n sweets in a bag, 6 of which are orange. If the probablility of eating 2 orange sweets from the bag, one after the other, is 1/3, show that n^2 - n - 90 = 0. State any assumptions made.

We are assuming that the sweets are selected at random. The question says that the sweets are eaten, so we are also assuming that they aren't put back into the bag. The total probability of selecting the ...

Answered by James B. • Maths tutor

3324 Views