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What is the determinant of a 2 by 2 matrix?

Let A by any 2 by 2 matrix and the top left, top right, bottom left and bottom right entries be a, b, c and d respectively. The determinant for matrix A would be ad-bc.

Answered by Lin G. • Maths tutor

3071 Views

Make x the subject of the equation. 7xy+6 = 18x+3y+7

Put all the terms which contain x onto one side of the equation.-6 from both sides of the equation and -18x from both sides of the equation to get7xy-18x = 3y+7-6Simplify if possible7xy-18x = 3y+1Take the...

Answered by Lucy M. • Maths tutor

2645 Views

Prove that the sum of four consecutive whole numbers will always be even.

First, check you understand what the question's asking by determining the key words. Next, try a couple of examples to convince yourself that the statement does in fact work, i.e 1+2+3+4=10, which is even...

Answered by Emma B. • Maths tutor

23716 Views

Solve the simultaneous equations: x^2 + y^2 = 10 and x + 2y = 5

1.)x² + y² = 10 2.)x + 2y = 5. Rearrange 2nd equation: x = 5 - 2y. Substitute back into 1st equation: (5 - 2y)²+ y² = 10. Multiply out brackets: 4y²

Answered by Edward W. • Maths tutor

8933 Views

What exactly is pi?

Pi is the ratio between a the circumference and the diameter of a circle. It's just a number which happens to describe this ratio for any circle you can think of. Let me explain, using the whiteboard...

Answered by Harry B. • Maths tutor

2430 Views