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Solve the simultaneous equation: 3x+y=-2, -7x+5y=34.

3x+y=-2 ...1)

-7x+5y=34 ...2)

Using the substitution method:

Rearrange equation 1):

y=-3x-2 ...1))

substitute equa...

Answered by Shaan J. • Maths tutor

8724 Views

If f(x) = 4x - 7 and f(c) = 9, find the value of c.

To find the value of c, we need to find the value of x in the following: 4x - 7 = 9.

Add seven to both sides: 4x = 16

Divide by 4: x = 4

Answered by Andrew B. • Maths tutor

6556 Views

Given that 5cos^2(x) - cos(x) = sin^2(x), find the possible values of cos(x) using a suitable quadratic equation.

First, need to get all the terms in the equation to be the same. Using the following identity, it is possible to achieve this:

sin²(x) + cos²(x) = 1

1 ...

Answered by Andrew B. • Maths tutor

8855 Views

Factorise and solve x^2 – 8x + 15 = 0

This equation is of the form ax² + bx + c = 0 (where a = 1, b = -8 and c = 15). To help solve it, find two numbers that add to give the value of b (the 'sum') and also when multiplied togeth...

Answered by Andrew B. • Maths tutor

12568 Views

There are n sweets in a bag, 6 are orange, the rest yellow. Two sweets are taken out individually without replacement. The probability of which is 1/3. show n²-n-90=0

Firstly, you need to consider the type of problem we are dealing with. This is actually just a tree diagram type question. note that the sweets are not replaced.

Letting n = number of swe...

Answered by Joel R. • Maths tutor

4784 Views