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The new reading for James' electricity bill is 7580, and the old reading is 7510, the price per unit is 13p, how much does James have to pay for his electricity?

This question is tricky/unfair because you need to understand how meters work. The old reading was the last time the electricity bill was paid for, so the first thing you need to do is 7580-7510= 70. So that...
MZ
Answered by Michal Z. • Maths tutor
3293 Views

Solve simultaneously 2x + 3y = 18 and y = 3x – 5 to find the value of x and y.

sub the y value into the first eqn 2x + 3(3x-5) = 18 expand the brackets 2x +9x-15 = 18 add up the x values 11x -15 = 18 add 15 to both sides to cancel it out on the l.h.s 11x = 33 divide by 11 to get value ...
JG
Answered by Jessica G. • Maths tutor
4156 Views

Given that x = cot y, show that dy/dx = -1/(1+x^2)

Identify that we are looking at dy/dx, not dx/dy and realise the relationship that dy/dx=1/(dx/dy)2)Try find dx/dy;cot = 1/tan or (tan) -1 Hence, x=(tan y ) -1 implying dx/dy = (-1)(tan y) -2 (sec 2 y ) =(-1...
JF
Answered by Jacob F. • Maths tutor
12699 Views

Work out the gradient of the tangent to the curve (y=x^2-x-2) at the point where x=2

y=x^2-x-2y=(x+1)(x-2)The gradient (dy/dx) measures the rate of the change in y with respect to x. So this can be used to help us find the gradient of a function at any point along it. The question asks the t...
OG
Answered by Oriane G. • Maths tutor
4825 Views

Define Economies of Scale stating an instance when this might occur.

This is when a company's costs decrease as a result of increased production. This may occur when two companies decide to merge in order to grow the business by pooling their individual resources. As a result...
SM
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