Top answers

Use factorisation to solve the equation x^2+5x+6=0

As we are considering a quadratic equation, we are looking for two values of x that make the equation equal to 0. To factorise, first look to the constant term (the term without any x) to find 2 numbers that...
NC
Answered by Niamh C. • Maths tutor
4225 Views

Explain why sulfur deviates from the general trend in ionisation energies across period 3.

Sulfur has the electronic structure [Ne]3s2 3p4. This means there are 2 electrons in the same p orbital. These repel each other making it easier to remove the electron causing the ionisation energy to be low...
AM
Answered by Angus M. • Chemistry tutor
15366 Views

Describe how and explain why vegetable oils are hardened for use in foods

Vegetable oils are unsaturated because they contain lots of carbon-carbon double bonds. If we react them with hydrogen at 60oC in the presence of nickel catalyst they will become saturated, also called harde...
AM
Answered by Angus M. • Chemistry tutor
2978 Views

If y=x^3+9x, find gradient of the tangent at (2,1).

To find the gradient of the tangent, we can differentiate to give dy/dx=3x^2+9. We can now put in x=2 to find the gradient at (2,1): 3(2)^2+9=21. Therefore the gradient is 21 at (2,1).
AM
3034 Views

Solve 7x-4=8+5x

First bring all the x terms to one side by taking 5x from each side, this gives 2x-4=8. Now put all the number terms on the other side by adding 4 to each side, this gives 2x=12. We can now divide both sides...
AM
Answered by Angus M. • Maths tutor
4224 Views